New Drug Approvals

Home » Uncategorized

Category Archives: Uncategorized


Blog Stats

  • 1,777,740 hits

Flag and hits

Flag Counter

Enter your email address to follow this blog and receive notifications of new posts by email.

Join 2,071 other followers

Follow New Drug Approvals on


Flag Counter


Read all about Organic Spectroscopy on ORGANIC SPECTROSCOPY INTERNATIONAL 

Enter your email address to follow this blog and receive notifications of new posts by email.

Join 2,071 other followers



DR ANTHONY MELVIN CRASTO, Born in Mumbai in 1964 and graduated from Mumbai University, Completed his Ph.D from ICT, 1991,Matunga, Mumbai, India, in Organic Chemistry, The thesis topic was Synthesis of Novel Pyrethroid Analogues, Currently he is working with GLENMARK PHARMACEUTICALS LTD, Research Centre as Principal Scientist, Process Research (bulk actives) at Mahape, Navi Mumbai, India. Total Industry exp 29 plus yrs, Prior to joining Glenmark, he has worked with major multinationals like Hoechst Marion Roussel, now Sanofi, Searle India Ltd, now RPG lifesciences, etc. He has worked with notable scientists like Dr K Nagarajan, Dr Ralph Stapel, Prof S Seshadri etc, He did custom synthesis for major multinationals in his career like BASF, Novartis, Sanofi, etc., He has worked in Discovery, Natural products, Bulk drugs, Generics, Intermediates, Fine chemicals, Neutraceuticals, GMP, Scaleups, etc, he is now helping millions, has 9 million plus hits on Google on all Organic chemistry websites. His friends call him worlddrugtracker. His New Drug Approvals, Green Chemistry International, All about drugs, Eurekamoments, Organic spectroscopy international, etc in organic chemistry are some most read blogs He has hands on experience in initiation and developing novel routes for drug molecules and implementation them on commercial scale over a 29 year tenure till date Aug 2016, Around 30 plus products in his career. He has good knowledge of IPM, GMP, Regulatory aspects, he has several International patents published worldwide . He has good proficiency in Technology transfer, Spectroscopy, Stereochemistry, Synthesis, Polymorphism etc., He suffered a paralytic stroke/ Acute Transverse mylitis in Dec 2007 and is 90 %Paralysed, He is bound to a wheelchair, this seems to have injected feul in him to help chemists all around the world, he is more active than before and is pushing boundaries, He has 9 million plus hits on Google, 2.5 lakh plus connections on all networking sites, 25 Lakh plus views on dozen plus blogs, He makes himself available to all, contact him on +91 9323115463, email, Twitter, @amcrasto , He lives and will die for his family, 90% paralysis cannot kill his soul., Notably he has 13 lakh plus views on New Drug Approvals Blog in 212 countries...... , He appreciates the help he gets from one and all, Friends, Family, Glenmark, Readers, Wellwishers, Doctors, Drug authorities, His Contacts, Physiotherapist, etc

Personal Links

Verified Services

View Full Profile →


Flag Counter

Nefopam Hydrochloride, Нефопама Гидрохлорид, 塩酸ネホパム



  • Molecular Formula C17H19NO
  • Average mass 253.339 Da
Cas 13669-70-0 [RN]
1H-2,5-Benzoxazocine, 3,4,5,6-tetrahydro-5-methyl-1-phenyl-
237-148-2 [EINECS]
Image result for Nefopam Hydrochloride, Fenazoxine
Derivative Type: Hydrochloride
CAS Registry Number: 23327-57-3
Additional Names: Fenazoxine
SCX-001,  R-738
Non-Opioid Analgesics
Wound-Healing Agents
Biocodex, 1983 pain
Нефопама Гидрохлорид

Nefopam, sold under the brand names Acupan among others, is a painkilling medication. It is primarily used to treat moderate, acuteor chronic pain[3]

It is believed to work in the brain and spinal cord to relieve pain. There it is believed to work via rather unique mechanisms. Firstly it increases the activity of the serotoninnorepinephrine and dopamineneurotransmitters involved in, among other things, pain signaling. Secondly, it modulates sodium and calcium channels, thereby inhibiting the release of glutamate, a key neurotransmitter involved in pain processing.[4

Medical uses

Nefopam has additional action in the prevention of shivering, which may be a side effect of other drugs used in surgery.[5] Nefopam was significantly more effective than aspirin as an analgesic in one clinical trial,[6] although with a greater incidence of side effects such as sweating, dizziness and nausea, especially at higher doses.[7][8] Nefopam is around a third to half the potency and slightly less effective as an analgesic compared to morphine,[9][10][11] or oxycodone,[12] but tends to produce fewer side effects, does not produce respiratory depression,[13] and has much less abuse potential, and so is useful either as an alternative to opioids, or as an adjunctive treatment for use alongside opioid(s) or other analgesics.[11][14] Nefopam is also used to treat severe hiccups.[15]


Nefopam is contraindicated in people with convulsive disorders, those that have received treatment with irreversible monoamine oxidase inhibitors such as phenelzinetranylcypromine or isocarboxazid within the past 30 days and those with myocardial infarctionpain, mostly due to a lack of safety data in these conditions.[16]

Side effects

Common side effects include nausea, nervousness, dry mouth, light-headedness and urinary retention.[16] Less common side effects include vomiting, blurred vision, drowsiness, sweating, insomnia, headache, confusion, hallucinations, tachycardia, aggravation of angina and rarely a temporary and benign pink discolouration of the skin or erythema multiforme.[16]


Overdose and death have been reported with nefopam,[17] although these events are less common with nefopam than with opioid analgesics.[18] Overdose usually manifests with convulsionshallucinationstachycardia, and hyperdynamic circulation.[16] Treatment is usually supportive, managing cardiovascular complications with beta blockers and limiting absorption with activated charcoal.[16]


It has additive anticholinergic and sympathomimetic effects with other agents with these properties.[16] Its use should be avoided in people receiving some types of antidepressants (tricyclic antidepressants or monoamine oxidase inhibitors) as there is the potential for serotonin syndrome or hypertensive crises to result.[16]


Site Ki (nM)
NET 33
DAT 531
5-HT2A 1,685
5-HT2B 330
5-HT2C 56

The mechanism of action of nefopam and its analgesic effects are not well understood, although inhibition of the reuptake of serotoninnorepinephrine, and to a lesser extent dopamine (that is, acting as an SNDRI) is thought to be involved.[21][4] It also reduces glutamate signaling via modulating sodium and calcium channels.[22][4]


The absolute bioavailability of nefopam is low.[1] It is reported to achieve therapeutic plasma concentrations between 49 and 183 nM.[20] The drug is approximately 73% protein-bound across a plasma range of 7 to 226 ng/mL (28–892 nM).[1] The metabolism of nefopam is hepatic, by Ndemethylation and via other routes.[1] Its terminal half-life is 3 to 8 hours, while that of its active metabolite, desmethylnefopam, is 10 to 15 hours.[1] It is eliminated mostly in urine, and to a lesser extent in feces.[1]


Nefopam is a cyclized analogue of orphenadrinediphenhydramine, and tofenacin, with each of these compounds different from one another only by the presence of one or two carbons.[23][24][25] The ring system of nefopam is a benzoxazocine system.[23][26]

Society and culture

Recreational use

Recreational use of nefopam has been reported,[17] although this is less common than with opioid analgesics.[18]


Image result for Nefopam synthesis


ES 8605495

The reaction of 2-benzoylbenzoic acid (I) with SOCl2 in CHCl3, benzene or DMF gives the corresponding acyl chloride (II), which is condensed with ethanolamine (III) by means of TEA in CHCl3 to yield the amide (IV). The reduction of (IV) with LiAlH4 in THF affords the diol (V), which is cyclized by means of Ts-OH in refluxing benzene to provide 1-phenyl-3,4,5,6-tetrahydro-1H-2,5-benzoxazocine (VI). Finally, this compound is methylated by means of dimethyl sulfate in refluxing benzene, or by means of formaldehyde in hot dioxane/water. Alternatively, the cyclization of N-[2-[1-[2-(chloromethyl)phenyl]-1-phenylmethoxy]ethyl]-N-methylamine (VII) by means of pyridine in refluxing acetonitrile gives also the target benzoxazocine


KE 8201564


ES 8104800

The reaction of 3-phenylphthalide (I) with N-methylethanolamine (II) in refluxing benzene gives N-(2-hydroxyethyl)-2-(1-hydroxy-1-phenylmethyl)-N-methylbenzamide (III), which is cyclized by means of Ts-OH in refluxing toluene to yield 5-methyl-1-phenyl-3,4,5,6-tetrahydro-1H-2,5-benzoxazocin-6-one (IV). Finally this compound is reduced with LiAlH4 in refluxing THF to afford the target benzoxazocine. In an alternative method, the reduction of 2-benzoyl-N-(2-hydroxyethyl)-N-methylbenzamide (V) by means of sodium bis(2-methoxyethoxy)aluminum hydride in refluxing toluene gives the diol (VI), which is then cyclized by means of Ts-OH in refluxing toluene, or by means of aq. 48% HBr in hot chloroform to afford the target benzoxazocine

The reaction of 2-benzoylbenzoic acid (I) with refluxing SOCl2 gives the corresponding acyl chloride (II), which is condensed with 2-(methylamino)acetic acid (III) in benzene to yield the N-(2-benzoylbenzoyl)-N-methylglycine (IV). The reduction of (IV) by means of LiAlH4 in refluxing THF affords the diol (V), which is finally cyclized by means of PPA at 80 C to provide the target benzoxazocine.


US 4208349

PATENT imgb0001

This compound is useful as an intermediate in producing the pharmacologically valuable 3,4,5,6-tetrahydro-5-methyl-l-phenyl-lH-2,5-benzoxazocine- hydrochloride, or nefopam, which is used, e.g. as a muscle relaxant, an analgesic or antidepressant drug.

Processes for producing the compound of formula I are already known. For instance, according to German Patent 1,620,198, phthalic aldehyde is used as a starting material. According to the German Patent, the phthalic aldehyde is reacted with a Grignard reagent, phenylmagnesiumbromide, and an N-substituted aminoalcohol is coupled to the reaction mixture, to produce a product of formula:

Figure imgb0002

This product is catalytically hydrogenated with the aid of Pd/C, Pt or Raney-Ni, and a product of formula I is obtained.

In another method, according to the German Patent 1,620,198, o-benzoylbenzoic acid is used as a starting material, which is converted by means of thionylchloride into an acid chloride. To this acid chloride is then coupled methylethanolamine, and N-(2-hydroxyethyl)-N-methyl-o-benzoylbenzamide is obtained as an intermediate, which is reduced using LiAlH4 and an end-product of formula I is produced.

According to United States Patent 3,487,153 o-benzoylbenzoic acid amide is used as starting material to produce the intermediate. With the aid of thionylchloride the corresponding acid chloride is formed, which is allowed to react with N-methyl-2-aminoethanol. The so-produced N-(2-hydroxyethyl)-N-methyl-o-benzoylbenzamide is reduced with LiAlH4 to 2{[N-(2-hydroxyethyl)-N-methyl)amino}-methylbenzhydrol.

According to German Offenlegungschrift 2,834,312 o-benzoylbenzoic acid is used as a starting material, which is allowed to react with phosphorus trichloride in dichloroethane. The acid chloride formed is allowed to react with triethylamine and N-methyl-2-hydroxyethyl- amine, after which N-(2-hydroxyethyl)-N-methyl-o-benzoylbenzamide is formed. This compound is treated with phosphorus trichloride (at pH=7.0) and N-(2-chloroethyl)-N-methyl-o-benzoylbenzoic amide is obtained, which is then reduced with NaBH4 in acetic acid. By these means 2-{[N-(2-hydroxyethyl)-N-methyl]-amino?-methylbenzhydrol is obtained.

According to Finnish Patent No. 54793, which corresponds to Canadian Patent 982,608, a compound of formula III is used as starting material, which is reduced with NaBH4 to a corresponding benzhydrol derivative of formula IV, which is then allowed to react with an alkylamine to an a-substituted 2-aminomethyl- benzylalcohol of formula V. The abovementioned Patent does not concern either the preparation of nefopam or its intermediates

Figure imgb0003

When reviewing the abovementioned Patents, i.e. German Patent 1,620,198 and United States Patent 3,487,153, one can observe the disadvantage that catalytic hydrogenation with palladium on charcoal, platinum or Raney-Ni, or lithium aluminium hydride are to be used to reduce the starting materials. This latter reagent is expensive and reacts with water very intensely, so that even a little humidity in the working surroundings or in the solvents can cause a fire. Explosive hydrogen is also produced by the reaction. Grignard reactions and catalytic hydrogenations are technically difficult to perform on a large scale. Moreover, the price of o-phthalic aldehyde is high.

According to the method described in German Offenlegungschrift 2,834,312 the reducing of the amide- carbonyl group with sodium borohydride in acetic acid requires, however, great additional amounts or about 2-3 equivalents of sodium borohydride. The yield of the reaction is quite poor (about 50-55%) and the reaction time is long, so the production costs become high. Moreover, the number of synthetic reaction steps is high and the use of phosphorus trichloride especially on a production scale is difficult.

In the method according to the Finnish Patent 54793, which corresponds to the Canadian Patent 982,608, a benzophenone derivative (of formula III) is reduced with NaBH4 to the corresponding benzhydrol derivative (formula IV). This compound is, however, unstable because of the methylene halogen group in o-position, especially when R1 = H in formula IV. On storing for only a short time hydrogenchloride gas is released and a very stable 5-ring ether is formed, which is useless. The use of this method on a large scale is therefore almost impossible, because the intermediate is impossible to isolate fast enough to obtain at least a reasonable amount of the end product.

The present invention provides a process for the preparation of 2-{[N-(2-hydroxyethyl)-N-methyl]-amino}-methylbenzhydrol (as such or as an acid addition salt) which comprises reacting 2-chloromethylbenzophenone with 2-methylaminoethanol to give 2-J[N-(2-hydroxyethyl)-N-methyl]-amino}-methylbenzophenone (as such or as a salt), and reducing the latter with sodium borohydride to give 2-{[N-2-(hydroxyethyl)-N-methyl)-aminol}-methylbenzhydrol (as such or as an acid addition salt). The 2-chlorobenzophenone (of formula VI) is brought to react with methylethanolamine in the presence of e.g. sodium carbonate, and 2-{[N-(2-hydroxyethyl)-N-methyl]-amino}- methylbenzophenone (of formula VII) is formed. This substance is theoreduced with sodium borohydride to 2-{(N-(hydroxyethyl)-N-methyl]-amino}-methylbenzhydrol (of formula VIII), as shown below:

Figure imgb0004

Figure imgb0005

The starting material, 2-chloromethyl benzophenone, can be produced in known manner by halogenating the corresponding 2-methylbenzophenone (Monatshefte far Chemie 99, 1990-2003, 1968) or 2-hydroxymethylbenzophenone, of which the former is commercially available and the latter can be produced in known manner from the phthalide (see British Patent 1,526,331). The compound of formula VII is new, and as such a feature of the invention.

The following Examples illustrate the invention.


8.50 g (0.037 mol) 2-chloromethylbenzophenone is dissolved in 40 ml ethylalcohol, and 4.0 g sodium carbonate and 2.80 g (0.037 mol) 2-methylaminoethanol are added, The mixture is boiled for 3 hours and the salts formed are filtered off from the cooled solution. A pure reaction product is obtained when the ethanol is evaporated from the solution and the product is crystallized as a hydrochloride salt from a mixture of diethylether and alcohol. The yield is 10.7 g (95 %) of 2{(N-(2-hydroxyethyl)-N-methyl]-amino}- methylbenzophenone as a crystalline powder, m.p. 135-136 C.

This compound, as the free base, shows the following N M R spectrum (in cDC13 using T M S as internal reference): 7.8 – 7.1 (aromatic), 3.5 (singlet), 3.4 (triplet), about 2.6 (singlet), 2.3 (triplet),1.9 (singlet). Its infra-red spectrum shows maxima at the following frequencies (cm-1): 680, 720, 760, 910, 1010, 1060, 1140, 1230, 1260, 1300, 1430, 1560,1580, 1640, 2760, 2920, 3030 and 3400.


10.0 g (0.033 mol) of the hydrochloride salt prepared in Example 1 are dissolved in a mixture comprising 15 ml water, 60 ml methanol and 3.5 g sodium hydroxide. To the mixture is added 0.65 g sodium borohydride and the solution is mixed for half an hour at room temperature.

The solution is acidified with concentrated hydrochloric acid and the methanol is evaporated in vacum. 40 ml of water is added, the pH of the water solution is adjusted with diluted sodium hydroxide solution to an alkaline reaction and the product is extracted into chloroform. The chloroform extracts are washed well with water, dried over sodium sulphate and evaporated to dryness. The product is separated by precipitating as a hydrochloride salt from a mixture of diethylether and ethylalcohol. The yield is 9.8 g (96 %) of 2-{(N-(2-hydroxyethyl)-N-methyl]-amino}- methylbenzhydrol as a crystalline powder, m.p. 128-133 C.

Cited Patent Filing date Publication date Applicant Title
DE2834312A1 * Aug 4, 1978 Feb 15, 1979 Riker Laboratories Inc Verfahren zur herstellung von 2 eckige klammer auf n-(2-hydroxyaethyl)- n-niederalkylaminomethyl eckige klammer zu -benzhydrolen
ES485471A * Title not available
1 * CHEMICAL ABSTRACTS Vol. 94, No. 11, 16 March 1981 Columbus, Ohio, USA FARMA-LEPORI “2-(n-2-Hydroxyethylmethylaminomethyl)benzhydrol” page 690, column 2, Abstract No. 83757s & ES – A – 485 471.
Citing Patent Filing date Publication date Applicant Title
CN102363610A * Nov 1, 2011 Feb 29, 2012 安徽万和制药有限公司 New method for synthesizing nefopam hydrochloride
CN102924320A * Nov 15, 2012 Feb 13, 2013 南京海陵中药制药工艺技术研究有限公司 Method for preparing nefopam intermediate I
CN102924320B * Nov 15, 2012 Jan 14, 2015 南京海陵中药制药工艺技术研究有限公司 Method for preparing nefopam intermediate I


CN 102363610

Example 1:

[0043] o-benzoyl benzoate 120g, phosphorus trichloride 30g, 220g of the mixture placed in a reaction flask dichloroethane, Mh was stirred at room temperature, the supernatant was separated to give acid chloride solution A;

[0044] A solution of this acid chlorine solution to 5 ° C and at a pre-filled with N- methyl ethanolamine 44g, triethylamine 64g, 200g dichloroethane reaction flask, stirred at room temperature drop after 10h, get amine solution B;

[0045] B in the amine solution and then dropping phosphorus trichloride 33g, reaction at 65 ° C 2h, washed with water cooling, the solution was washed with a dilute solution of sodium hydroxide, to sub-alkaline layer chloride solution C.

[0046] In the reaction flask was added a certain amount of potassium borohydride; potassium borohydride to mass, and then the mixture was added 15% acetic acid and dichloroethane (solvent of acetic acid mass ratio of 1: 1); to potassium borohydride mass, and then added dropwise to obtain 45% of the chlorination reaction chloride solution C, stirring the reaction was heated to reflux for 2h, pre-reduction; with potassium borohydride mass, further addition of 10% acetic acid and dichloroacetyl alkane mixture (mass ratio of acetic acid to solvent is 1: 1), the reaction was stirred Ih; in reducing mass, and finally the mixture was added dropwise 45% obtained by chlorinating liquid the chlorination reaction C with acetic acid (chloride quality liquid C and acetic acid ratio of 1: 1), the reaction was stirred tank for the final reduction. Plus 40% hydrolyzed sodium hydroxide solution, the organic layer was separated D

[0047] The separated organic layer D was cooled to room temperature and added slowly to 65 ° C hydrobromide reaction 6h, the reaction is completed, cooled to 0 ° C, and filtered to give the cyclization product E.

[0048] The cyclization to give the reaction product E was added sodium hydroxide solution and then dropwise addition of concentrated hydrochloric acid, to obtain Nefopam.

[0049] Example 2:

[0050] o-benzoyl benzoate 120g, phosphorus trichloride 30g, 220g of the mixture placed in a reaction flask dichloroethane, Mh was stirred at room temperature, the supernatant was separated to give acid chloride solution A;

[0051] A solution of this acid chlorine solution to 5 ° C and at a pre-filled with N- methyl ethanolamine 44g, triethylamine 64g, 200g dichloroethane reaction flask, stirred at room temperature drop after 10h, get amine solution B;

[0052] B in the amine solution and then dropping phosphorus trichloride 33g, reaction at 65 ° C 2h, washed with water cooling, the solution was washed with a dilute solution of sodium hydroxide, to sub-alkaline layer chloride solution C.

[0053] In the reaction flask was added a certain amount of potassium borohydride; potassium borohydride to mass, and then the mixture was added 25% acetic acid and dichloroethane (solvent of acetic acid mass ratio of 1: 1); to potassium borohydride mass, then dropping to 50% of the chlorination reaction chloride solution C, stirring heated to reflux for 2h, pre-reduction; potassium borohydride mass, then add 20% acetic acid and dichloroethane alkane mixture (mass ratio of acetic acid to solvent is 1: 1), the reaction was stirred Ih; in reducing mass, and finally the mixture was added dropwise a 50% solution chlorination reaction C and obtained by chlorinating acetic acid (chloride quality liquid C and acetic acid ratio of 1: 1), the reaction was stirred tank for the final reduction. Plus 40% hydrolyzed sodium hydroxide solution, the organic layer was separated D

[0054] The separated organic layer D was cooled to room temperature and added slowly with stirring at 65 ° C the reaction hydrobromide 8h, the reaction is completed, cooled to 0 ° C, and filtered to give the cyclization product E.

[0055] The cyclization to give the reaction product E was added sodium hydroxide solution and then dropwise addition of concentrated hydrochloric acid, to obtain Nefopam.

[0056] The applicant stated the above embodiments of the present invention will be described in detail the process equipment and process of the present invention, but the invention is not limited to the above detailed process equipment and process, that does not mean that the present invention must rely on such details process equipment and processes to be implemented. Skill in the art should be appreciated that any improvement in the present invention, the present invention is the product of the raw materials equivalents and adding auxiliary components, choice of specific ways, and fall within the scope of the public of the scope of the present invention.

Figure CN102363610AD00051

Figure CN102363610AD00052

Figure CN102363610AD00053

Cited Patent Filing date Publication date Applicant Title
EP0033585A1 * Jan 9, 1981 Aug 12, 1981 Farmos-Yhtyma Oy A process for the preparation of a benzhydrol derivative and a novel intermediate for use therein
US3978085 * Mar 7, 1975 Aug 31, 1976 Riker Laboratories, Inc. Process for benz[f]-2,5-oxazocines
US4208349 * Mar 5, 1979 Jun 17, 1980 Riker Laboratories, Inc. Process for the preparation of 2-[N-(2-hydroxyethyl)-N-lower alkylaminomethyl]benzhydrols
1 * 胡颂凯: “镇痛药盐酸苯并噁唑辛的合成“, 《医药工业》, no. 8, 28 August 1984 (1984-08-28)
Citing Patent Filing date Publication date Applicant Title
CN102924320A * Nov 15, 2012 Feb 13, 2013 南京海陵中药制药工艺技术研究有限公司 Method for preparing nefopam intermediate I


1H NMR (400 MHz, D2O, δ/ppm): 7.36–7.25 (m, 6H, arom H), 7.21–7.18 (m, 2H, arom H), 7.12–7.10 (m, 1H, arom H), 5.89 (s, 1H, Aryl–CH–Aryl), 5.45 (d, 1H, Aryl–CH(H)–N–, J = 12.8 Hz), 4.34–4.27 (m, 1H, –CH(H)–O–), 4.21 (d, 1H, Aryl–CH(H)–N–, J = 13.2 Hz), 4.05–4.00 [m (dt), 1H, –CH(H)–O–, J = 6.8 Hz and J = 3.6 Hz], 3.30-3.23 (m, 1H, –CH(H)– N–), 3.08–3.02 [m (dt), 1H, –CH(H)–N–, J = 7.2 Hz and J = 3.6 Hz), 2.87 (s, 3H, –CH3).

13C NMR (100 MHz, D2O, δ/ppm): 142.4, 141.1, 134.3, 130.5, 129.1, 129.0 (2C), 128.7, 128.4, 127.7 (2C), 125.3, 85.3, 64.9, 58.3, 50.5, 41.6

Powder XRD spectra and data of pure API (1). ABOVE


5-Methyl-1-phenyl-3,4,5,6-tetrahydro-1H-2,5-benzoxazocine Hydrochloride (1

White crystalline solid, mp 248–251 °C, [α]D20 = −0.016 (c 1.0, H2O).
1H NMR (400 MHz, D2O, δ/ppm): 7.36–7.25 (m, 6H, arom H), 7.21–7.18 (m, 2H, arom H), 7.12–7.10 (m, 1H, arom H), 5.89 (s, 1H, Aryl–CH–Aryl), 5.45 (d, 1H, Aryl–CH(H)–N–, J = 12.8 Hz), 4.34–4.27 (m, 1H, −CH(H)–O−), 4.21 (d, 1H, Aryl–CH(H)–N–, J = 13.2 Hz), 4.05–4.00 (m (dt), 1H, −CH(H)–O–, J = 6.8 Hz and J = 3.6 Hz), 3.30–3.23 (m, 1H, −CH(H)–N−), 3.08–3.02 (m (dt), 1H, −CH(H)–N–, J = 7.2 Hz and J = 3.6 Hz), 2.87 (s, 3H, −CH3).
13C NMR (100 MHz, D2O, δ/ppm): 142.4, 141.1, 134.3, 130.5, 129.1, 129.0 (2C), 128.7, 128.4, 127.7 (2C), 125.3, 85.3, 64.9, 58.3, 50.5, 41.6.
ESI-MS (m/z): 254.20 (M + H)+. CHN analysis data (wt %): Anal. Calcd for C17H19NO·HCl or C1


Old is Gold? Nefopam Hydrochloride, a Non-opioid and Non-steroidal Analgesic Drug and Its Practical One-Pot Synthesis in a Single Solvent for Large-Scale Production

Mohan Reddy Bodireddy, Kiran Krishnaiah, Prashanth Kumar Babu, Chaithanya Bitra, Madhusudana Rao Gajula*, and Pramod Kumar*
Chemical Research Division, API R&D Centre, Micro Labs Ltd., Plot No.43-45, KIADB Industrial Area, Fourth Phase, Bommasandra-Jigani Link Road, Bommasandra, Bangalore-560 105, Karnataka, India
Org. Process Res. Dev., Article ASAP
DOI: 10.1021/acs.oprd.7b00228

*Tel.: 0811 0415647, ext. 245; + 91 9008448247 (mobile). E-mail:, *E-mail:

 Abstract Image

Nefopam hydrochloride is extensively used in most of the European countries until today as an analgesic because of its non-opiate (non-narcotic) and non-steroidal action with fewer side effects compared with opioid and other analgesics, which cause more troublesome side effects. A multikilogram synthesis of nefopam hydrochloride has been achieved in one pot using a single solvent (toluene). A ≥99.9% purity of the active pharmaceutical ingredient (API) was achieved in excellent overall yield (≥79%). The one-pot, five-step synthetic process involves formation of an acid chloride (3) from benzoylbenzoic acid (2) followed by amidation (4), reduction (5), cyclization (6), and formation of the hydrochloride salt (1). The major advantages include (i) use of a single solvent, (ii) >90% conversion in each step, (iii) a cost-effective and operationally friendly process, (iv) averting the formation of genotoxic impurities, and (v) improved overall yield (≥79%) provided by the one-pot operation. For the first time, we report the characterization data of API 1, intermediates 34, and 5, and also a possible impurity (5a).



Title: Nefopam
CAS Registry Number: 13669-70-0
CAS Name: 3,4,5,6-Tetrahydro-5-methyl-1-phenyl-1H-2,5-benzoxazocine
Additional Names: 5-methyl-1-phenyl-1,3,4,6-tetrahydro-5H-benz[f]-2,5-oxazocine
Molecular Formula: C17H19NO
Molecular Weight: 253.34
Percent Composition: C 80.60%, H 7.56%, N 5.53%, O 6.32%
Literature References: A cyclized analog of orphenadrine and diphenhydramine, q.q.v.; representative of a new class of centrally acting skeletal muscle relaxants, the benzoxazocines. Prepn: NL 6606390 (1966 to Rexall); M. W. Klohs et al., US 3830803 (1974 to Riker). Pharmacology: Bassett et al., Br. J. Pharmacol. 37, 69 (1969); Klohs et al., Arzneim.-Forsch. 22, 132 (1972). Review of pharmacology and therapeutic efficacy: R. C. Heel et al., Drugs 19, 249-267 (1980).
Derivative Type: Hydrochloride
CAS Registry Number: 23327-57-3
Additional Names: Fenazoxine
Manufacturers’ Codes: R-738
Trademarks: Acupan (3M); Ajan (3M)
Molecular Formula: C17H19NO.HCl
Molecular Weight: 289.80
Percent Composition: C 70.46%, H 6.96%, N 4.83%, O 5.52%, Cl 12.23%
Properties: mp 238-242°. LD50 in mice, rats (mg/kg): 119, 178 orally; 44.5, 28 i.v. (Baltes).
Melting point: mp 238-242°
Toxicity data: LD50 in mice, rats (mg/kg): 119, 178 orally; 44.5, 28 i.v. (Baltes)
Therap-Cat: Analgesic; antidepressant.
Keywords: Analgesic (Non-Narcotic); Antidepressant; Bicyclics.


  1. Jump up to:a b c d e f g h i j k l m Sanga M, Banach J, Ledvina A, Modi NB, Mittur A (2016). “Pharmacokinetics, metabolism, and excretion of nefopam, a dual reuptake inhibitor in healthy male volunteers”. Xenobiotica46 (11): 1001–16. PMID 26796604doi:10.3109/00498254.2015.1136989.
  2. Jump up^ G. Seyffart (6 December 2012). Drug Dosage in Renal Insufficiency. Springer Science & Business Media. pp. 407–. ISBN 978-94-011-3804-8.
  3. Jump up^ Brayfield, A, ed. (27 October 2016). “Nefopam hydrochloride”MedicinesComplete. London, UK: Pharmaceutical Press. Retrieved 4 September 2017.
  4. Jump up to:a b c Girard, P; Chauvin, M; Verleye, M (January 2016). “Nefopam analgesia and its role in multimodal analgesia: A review of preclinical and clinical studies.”. Clinical and Experimental Pharmacology & Physiology43 (1): 3–12. PMID 26475417doi:10.1111/1440-1681.12506.
  5. Jump up^ Alfonsi P, Adam F, Passard A, Guignard B, Sessler DI, Chauvin M (January 2004). “Nefopam, a Non-sedative Benzoxazocine Analgesic, Selectively Reduces the Shivering Threshold”Anesthesiology100 (1): 37–43. PMC 1283107Freely accessiblePMID 14695722doi:10.1097/00000542-200401000-00010.
  6. Jump up^ Cohen A, Hernandez CM (1976). “Nefopam hydrochloride: new analgesic agent”. Journal of International Medical Research4 (2): 138–43. PMID 799984.
  7. Jump up^ Wang RI, Waite EM (July 1979). “The clinical analgesic efficacy of oral nefopam hydrochloride”. Journal of Clinical Pharmacology19 (7): 395–402. PMID 479385doi:10.1002/j.1552-4604.1979.tb02498.x.
  8. Jump up^ Pillans PI, Woods DJ (September 1995). “Adverse reactions associated with nefopam”. New Zealand Medical Journal108 (1008): 382–4. PMID 7566787.
  9. Jump up^ Sunshine A, Laska E (November 1975). “Nefopam and morphine in man”. Clinical Pharmacology and Therapeutics18 (5 Pt 1): 530–4. PMID 1102231.
  10. Jump up^ Phillips G, Vickers MD (October 1979). “Nefopam in postoperative pain”. British Journal of Anaesthesia51 (10): 961–5. PMID 391253doi:10.1093/bja/51.10.961.
  11. Jump up to:a b Heel RC, Brogden RN, Pakes GE, Speight TM, Avery GS (1980). “Nefopam: a review of its pharmacological properties and therapeutic efficacy”. Drugs19 (4): 249–67. PMID 6991238doi:10.2165/00003495-198019040-00001.
  12. Jump up^ Tigerstedt I, Tammisto T, Leander P (December 1979). “Comparison of the analgesic dose-effect relationships of nefopam and oxycodone in postoperative pain”. Acta Anaesthesiologica Scandinavica23 (6): 555–60. PMID 397711doi:10.1111/j.1399-6576.1979.tb01486.x.
  13. Jump up^ Gasser JC, Bellville JW (August 1975). “Respiratory effects of nefopam”. Clinical Pharmacology and Therapeutics18 (2): 175–9. PMID 1097153.
  14. Jump up^ Kapfer B, Alfonsi P, Guignard B, Sessler DI, Chauvin M (January 2005). “Nefopam and Ketamine Comparably Enhance Postoperative Analgesia”Anesthesia and Analgesia100 (1): 169–74. PMC 1283103Freely accessiblePMID 15616073doi:10.1213/01.ANE.0000138037.19757.ED.
  15. Jump up^ Bilotta, F; Rosa, G (December 2000). “Nefopam for severe hiccups.”. The New England Journal of Medicine343 (26): 1973–4. PMID 11186682doi:10.1056/nejm200012283432619.
  16. Jump up to:a b c d e f g “Data Sheet ACUPAN™ Nefopam hydrochloride 30 mg tablets 20 mg intramuscular injection” (PDF). Medsafe New Zealand. iNova Pharmaceuticals (New Zealand) Limited. 3 September 2007. Retrieved 10 March 2014.
  17. Jump up to:a b Bismuth, C; Fournier, PE; Bavoux, E; Husson, O; Lafon, D (September 1987). “[Chronic abuse of the analgesic nefopam (Acupan)].”. Journal de Toxicologie Clinique et Experimentale (in French). 7 (5): 343–6. PMID 3448182.
  18. Jump up to:a b Tracqui, A; Berthelon, L; Ludes, B (May 2002). “Fatal overdosage with nefopam (Acupan).” (PDF). Journal of Analytical Toxicology26 (4): 239–43. PMID 12054367doi:10.1093/jat/26.4.239.
  19. Jump up^ Roth, BL; Driscol, J. “PDSP Ki Database”Psychoactive Drug Screening Program (PDSP). University of North Carolina at Chapel Hill and the United States National Institute of Mental Health. Retrieved 14 August 2017.
  20. Jump up to:a b Gregori-Puigjané, E.; Setola, V; Hert, J; Crews, BA; Irwin, JJ; Lounkine, E; Marnett, L; Roth, BL; Shoichet, BK (18 June 2012). “Identifying mechanism-of-action targets for drugs and probes” (PDF). Proceedings of the National Academy of Sciences109 (28): 11178–11183. PMC 3396511Freely accessiblePMID 22711801doi:10.1073/pnas.1204524109.
  21. Jump up^ Bausch & Lomb (NZ) Ltd (17 May 2017). “NEW ZEALAND DATA SHEET ACUPAN(TM)” (PDF). Medsafe. New Zealand The Ministry of Health. Retrieved 4 September 2017.
  22. Jump up^ Kim, KH; Abdi, S (April 2014). “Rediscovery of nefopam for the treatment of neuropathic pain.”The Korean Journal of Pain27 (2): 103–11. PMC 3990817Freely accessiblePMID 24748937doi:10.3344/kjp.2014.27.2.103.
  23. Jump up to:a b Camille Georges Wermuth; David Aldous; Pierre Raboisson; Didier Rognan (1 July 2015). The Practice of Medicinal Chemistry. Elsevier Science. pp. 250–251. ISBN 978-0-12-417213-5.
  24. Jump up^ Walter Sneader (23 June 2005). Drug Discovery: A History. John Wiley & Sons. pp. 405–. ISBN 978-0-471-89979-2.
  25. Jump up^ Hugo Kubinyi; Gerhard MÃ1⁄4ller (6 March 2006). Chemogenomics in Drug Discovery: A Medicinal Chemistry Perspective. John Wiley & Sons. pp. 54–. ISBN 978-3-527-60402-9.
  26. Jump up^ Amy Cruz (2014). Therapeutic Hypothermia. CRC Press. pp. 176–. GGKEY:R0AP2X4GZYF.
Nefopam ball-and-stick model.png
Clinical data
Trade names Acupan
AHFS/ International Drug Names
Routes of
ATC code
Legal status
Legal status
  • AU: S4 (Prescription only)
  • UK: POM (Prescription only)
Pharmacokinetic data
Bioavailability Low[1]
Protein binding 70–75% (mean 73%)[1][2]
Metabolism Liver (Ndemethylation, others)[1]
Metabolites Desmethylnefopam, others[1]
Biological half-life Nefopam: 3–8 hours[1]
Desmethylnefopam: 10–15 hours[1]
Excretion Urine: 79.3%[1]
Feces: 13.4%[1]
CAS Number
PubChem CID
ECHA InfoCard 100.033.757
Chemical and physical data
Formula C17H19NO
Molar mass 253.34 g/mol
3D model (JSmol)

////////////Nefopam Hydrochloride, Fenazoxine, Нефопама Гидрохлорид, 塩酸ネホパム



“DRUG APPROVALS INT” CATERS TO EDUCATION GLOBALLY, No commercial exploits are done or advertisements added by me. This is a compilation for educational purposes only. P.S. : The views expressed are my personal and in no-way suggest the views of the professional body or the company that I represent

Novel lead compounds in pre-clinical development against African sleeping sickness

Med. Chem. Commun., 2017, 8,1872-1890
DOI: 10.1039/C7MD00280G, Review Article
Michael Berninger, Ines Schmidt, Alicia Ponte-Sucre, Ulrike Holzgrabe
This article reviews the recent progress in drug development against the African sleeping sickness.

Novel lead compounds in pre-clinical development against African sleeping sickness

 Author affiliations


Human African trypanosomiasis (HAT), also known as African sleeping sickness, is caused by parasitic protozoa of the genus Trypanosoma. As the disease progresses, the parasites cross the blood brain barrier and are lethal for the patients if the disease is left untreated. Current therapies suffer from several drawbacks due to e.g. toxicity of the respective compounds or resistance to approved antitrypanosomal drugs. In this review, the different strategies of drug development against HAT are considered, namely the target-based approach, the phenotypic high throughput screening and the drug repurposing strategy. The most promising compounds emerging from these approaches entering an in vivo evaluation are mentioned herein. Of note, it may turn out to be difficult to confirm in vitro activity in an animal model of infection; however, possible reasons for the missing efficacy in unsuccessful in vivo studies are discussed.

Conclusion  There are various starting points to generate hit compounds for the treatment of  African sleeping sickness. Especially stage II of HAT which is very hard to treat poses a  tough challenge for drug discovery programs as molecules inevitably need to cross the BBB. However, promising compounds (2, 15, and 17) are in the pipeline accomplishing these criteria for CNS mouse models, and in some cases even are  orally bioavailable (15 and 17). Especially the large phenotypic screening campaigns performed by the GNF, GlaxoSmithKline, DDU, and Sykes et al. resulted in promising hits discussed herein. Nevertheless, it is not always easy to translate results from in vitro studies into in vivo efficacy like shown in several of the mentioned studies. The reasons for in vivo failures are multilayered and might originate from (I) extensive  metabolism, (II) high plasma protein binding, (III) poor water solubility, (IV) efflux  transporters, (V) different sensitivity for particular strains, (VI) reduced permeability,  and (VII) growth inhibition rather than trypanocidal effects.

Image result for University of Würzburg Ulrike Holzgrabe

  • 1974 – 1981
    Studied chemistry and pharmacy at Marburg University and Kiel University
  • 1990 – 1999
    C3 professor at the University of Bonn, Germany
  • 1994 – 1995
    Visiting professor at the University of Erlangen-Nuremberg, Germany, and the University of Illinois at Chicago, USA
  • 1997 – 1999
    Vice-rector for teaching, studies and study reform at the University of Bonn
  • Since 1999
    C4/W3 professor of pharmaceutical chemistry at the University of Würzburg, Germany
  • Since 2009
    Dean of the Faculty of Chemistry and Pharmacy at the University of Würzburg

 Selected publications

  • Mohr, K. et al.: Rational design of dualsteric GPCR ligands: quests and promise. In: Br. J. Pharmacol. 159, 2010. pp. 997-1008.
  • Antony, J. et al.: Dualsteric GPCR targeting: a novel route to binding and signalling pathway selectivity. In: FASEB J. 23, 2009. pp. 442-450 (Listed as a “Must Read” by the “Faculty of 1000 Biology – the expert guide to the most important advances in biology”).
  • Niedermeier, S. et al.: A small-molecule inhibitor of Nipah virus envelope protein-mediated membrane fusion. In: J. Med. Chem. 52, 2009. pp. 4257-4265.
  • Göbel, T. et al.: In search of novel agents for therapy of tropical diseases and human immunodeficiency virus. In: J. Med. Chem. 51, 2008. pp. 238-250.
  • Hörr, V. et al.: Laser-induced fluorescence-capillary electrophoresis and fluorescence microplate reader measurement: two methods to quantify the effect of antibiotics. In: Anal. Chem. 79, 2007. pp. 7510-7518 (reviewed by D.L. Shenkenberg in Biophotonics International, Dec. 2007, pp. 57-58).
  • Disingrini, T. et al.: Design, synthesis, and action of oxotremorine-related hybrid-type allosteric modulators of muscarinic acetylcholine receptors. In: J. Med. Chem. 49, 2006. pp. 366-372.

 Selected projects

  • Characterisation of the oncogenic signalling network in multiple myeloma: development of targeted therapies, clinical research group KFO 216, inhibitors of the HSF/HSP system for treating multiple myeloma, since 2009
  • Identification, preparation and functional analysis of active ingredients for combating infectious diseases, SFB 630, small molecules for treating tropical infectious diseases, since 2003
  • Allosteric modulators and subtype-selective ligands of the muscarinic receptors, since 1991

 Membership in scientific bodies/juries

  • German Research Foundation (DFG) review-board member at the University of Würzburg, Germany, since 2009
  • Member of the Board of Pharmaceutical Science, International Federation of Pharmacy (FIP), since 2008
  • Member of the executive committee, European Federation for Pharmaceutical Sciences (Eufeps), since 2007
  • President of the German Pharmaceutical Society, 2004 – 2007
  • Member of the board of trustees of the University of Bonn, Germany, 2003 – 2007
  • Member of the scientific advisory board, German Federal Institute for Drugs and Medical Devices (BfArM), since 2002
  • Member of the German and European pharmacopoeia commissions, as well as president of several German and European pharmacopoeia boards, since 2001
 Image result for University of Würzburg Michael Berninger
Image result for University of Würzburg Michael Berninger
Image result for University of Würzburg Michael Berninger
Image result for University of Würzburg Institute of Pharmacy and Food Chemistry
Image result for University of Würzburg Institute of Pharmacy and Food Chemistry
Image result for University of Würzburg Institute of Pharmacy and Food Chemistry
Image result for University of Würzburg Institute of Pharmacy and Food Chemistry
///////////University of Würzburg,  Ulrike Holzgrabe

NNC 45-0781

Image result for NNC 45-0781

NNC 45-0781

Molecular Formula C27H29NO3
Molecular Weight 415.5241

CAS 207277-66-5

  • 2H-1-Benzopyran-7-ol, 3,4-dihydro-3-phenyl-4-[4-[2-(1-pyrrolidinyl)ethoxy]phenyl]-, cis-(-)-
  • (3S,4R)-3,4-Dihydro-3-phenyl-4-[4-[2-(1-pyrrolidinyl)ethoxy]phenyl]-2H-1-benzopyran-7-ol

2H-1-Benzopyran-7-ol, 3,4-dihydro-3-phenyl-4-(4-(2-(1-pyrrolidinyl)ethoxy)phenyl)-, (3S,4R)-

  • OriginatorNovo Nordisk
  • ClassOsteoporosis therapies; Pyrrolidines; Small molecules
  • Mechanism of ActionSelective estrogen receptor modulators


WO 9818776

WO 9818771

WO 2003063859

A quantitative structure activity relationship study on cis-3,4-diaryl hydroxy chromones as high affinity partial agonists for the estrogen receptor
Chemistry: An Indian Journal (2003), 1, (3), 207-214


EP 0937057; WO 9818771, EP 0937060; WO 9818776

Coumarin (III) was prepared by condensation of benzophenone (I) with phenylacetic acid (II) in the presence of Ac2O and Et3N. Reduction of the lactone function of (III) with LiAlH4, followed by acidic treatment furnished diaryl chromene (IV). Subsequent hydrogenation of (IV) over Pd/C gave rise to the racemic cis chromane (V), which was O-alkylated with 1-(2-chloroethyl) pyrrolidine (VI) producing the corresponding (pyrrolidinyl)ethoxy derivative. Resolution by means of active ditoluoyl tartaric acid yielded the desired (-)-enantiomer (VII). Finally, cleavage of the methoxy group using pyridine hydrochloride at 150 C provided the title compound.


Bioorg Med Chem 2002,10(1),125


The syntheses and in vitro pharmacological evaluation of a number of cis-3,4-diaryl-hydroxy-chromanes are reported, along with the results of a thorough in vivo profiling of the tissue-selective estrogen partial-agonist NNC 45-0781 [3, (−)-(3S,4R)-7-hydroxy-3-phenyl-4-(4-(2-pyrrolidinoethoxy)phenyl)chromane]. These studies showed that NNC 45-0781 is a very promising candidate for the prevention of post-menopausal osteoporosis, and the treatment of other health issues related to the loss of endogenous estrogen production.

The synthesis and pharmacological evaluation of a series of new tissue-selective estrogens, the cis-3,4-diaryl-hydroxy-chromanes, is described.

Unlabelled figure



(-)-(3S,4R)-7-Hydroxy-3-phenyl-4-(4-(2-pyrrolidinoethoxy)phenyl)chromane (3,=9a).

colorless powder 3, which contained 0.25 mol equiv of ethanol of crystallization; 0.90 g (27% yield),

mp 221–223 C.

1 H NMR (DMSOd6, 400 MHz) d: 1.60–1.73 (m, 4H), 2.40–2.50 (m, 4H), 2.69 (t, 2H), 3.47–3.57 (m, 1H), 3.92 (t, 2H), 4.14–4.25 (m, 2H), 4.32 (dd, 1H), 6.27 (dd, 1H), 6.30 (d, 1H), 6.44 (d, 2H), 6.60 (d, 2H), 6.65 (d, 1H), 6.70–6.80 (m, 2H), 7.09–7.20 (m, 3H), 9.25 (s, 1H).

MS (EI): 415 (M+), 84. HR-MS; calcd for C27H30NO3 (M+H+) 416.2225, found 416.2198. HR-MS; calcd for C28H32NO3 (M+H+) 430.2382, found 430.2376.

Chiral HPLC: Chiradex A, 5m, 2504 mm (Merck) column; eluent, 6:4 methanol/0.2% aqueous triethylammonium acetate buffer, pH=5.2; flow, 0.5 mL/min; UV 220 nm; Rt=19.2 min, >98%ee. Elemental analysis; calcd for C27H29NO3 0.25C2H5OH; C, 77.35; H, 7.20; N, 3.28%; found C, 77.39; H, 7.29; N, 3.12%. [a] 20 D=283 (c=1.004% in ethanol/3M HCl, 80:20). P.



Abstract Image

A highly enantioselective method for quick access to dihydrocoumarins is reported. The reaction involves a cooperative catalytic process with carbene and in situ generated Brønsted acid as the catalysts. α-Chloro aldehyde and readily available and stable o-hydroxybenzhydryl amine substrates were used to generate reactive azolium ester enolate and ortho-quinone methide (o-QM) intermediates, respectively, to form dihydrocoumarins with exceptionally high diastereo- and enantioselectivities. The catalytic reaction products can be easily transformed to valuable pharmaceuticals and bioactive molecules.

Carbene and Acid Cooperative Catalytic Reactions of Aldehydes and o-Hydroxybenzhydryl Amines for Highly Enantioselective Access to Dihydrocoumarins

 Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
 Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, People’s Republic of China
Org. Lett., Article ASAP
DOI: 10.1021/acs.orglett.7b02883
Publication Date (Web): October 25, 2017
Copyright © 2017 American Chemical Society

/////////////NNC 45-0781


(R)-(–)-Baclofen, Arbaclofen, STX 209, AGI 006

(R)-Baclofen.pngChemSpider 2D Image | Arbaclofen | C10H12ClNO2

(R)-(–)-Baclofen, Arbaclofen, STX 209, AGI 006

Chemical Names: (R)-Baclofen; Arbaclofen; 69308-37-8; (R)-4-Amino-3-(4-chlorophenyl)butanoic acid; (-)-Baclofen; D-Baclofen
Molecular Formula: C10H12ClNO2
Molecular Weight: 213.661 g/mol

 A GAMMA-AMINOBUTYRIC ACID derivative that is a specific agonist of GABA-B RECEPTORS. It is used in the treatment of MUSCLE SPASTICITY, especially that due to SPINAL CORD INJURIES. Its therapeutic effects result from actions at spinal and supraspinal sites, generally the reduction of excitatory transmission.

(R)-4-Amino-3-(4-chlorophenyl)butanoic acid

Benzeneporopanoic acid, (beta-(aminomethyl)-4-chloro-, (betaR)-


  • Benzenepropanoic acid, β-(aminomethyl)-4-chloro-, (R)-
  • (βR)-β-(Aminomethyl)-4-chlorobenzenepropanoic acid
  • (-)-Baclofen
  • (R)-(-)-Baclofen
  • (R)-4-Amino-3-(4-chlorophenyl)butanoic acid
  • (R)-4-Amino-3-(4-chlorophenyl)butyric acid
  • (R)-Baclofen
  • AGI 006
  • Arbaclofen
  • D-Baclofen
  • R-(-)-Baclofen
  • STX 209
  • l-Baclofen

Optical Rotatory Power, -1.76 °, Conc: 0.5 g/100mL; Solv: water (7732-18-5); Wavlen: 589.3 nm; Temp: 25 °C, REF …..Paraskar, Abhimanyu S.; Tetrahedron 2006, VOL62(20), PG4907-4916

Melting Point 196-197 °C Solv: isopropanol (67-63-0)

REF…..Paraskar, Abhimanyu S.; Tetrahedron 2006, VOL62(20), PG4907-4916


Image result for (R)-(–)-Baclofen

Arbaclofen, or STX209, is the R-enantiomer of baclofen. It is believed to be a selective gamma-amino butyric acid type B receptor agonist, and has been investigated as a treatment for autism spectrum disorder and fragile X syndrome in randomized, double blind, placebo controlled trials. It has also been investigated as a treatment for spasticity due to multiple sclerosis and spinal cord injury. Arbaclofen was investigated as a treatment for gastroesophageal reflux disease (GERD); however, with disappointing results.

AGI-006, a GABA(B) agonist, is currently in phase III clinical trials at Seaside Therapeutics for the treatment of social withdrawal in adolescents and adults with Fragile X Syndrome and for the treatment of autism spectrum disorders. AGI Therapeutics had been conducting clinical trials for the treatment of dyspepsia and for the treatment of delayed gastric emptying in diabetic patients; however, no recent development has been reported for this research. In 2015, Osmotica Pharmaceutical filed a NDA seeking approval of an extended-release formulation for the alleviation of spasticity due to multiple sclerosis.

AGI-006 is an oral formulation of arbaclofen, the R-isomer of baclofen. In 2012, a license option agreement was signed between Seaside and Roche by which the latter may commercialize the product upon completion of certain clinical development phases in fragile X syndrome and in autism spectrum disorders.

2D chemical structure of 1134-47-02D chemical structure of 1134-47-0Baclofen [USAN:USP:INN:BAN:JAN]

2D chemical structure of 28311-31-1Baclofen hydrochloride

2D chemical structure of 63701-55-3Arbaclofen hydrochloride

2D chemical structure of 63701-56-4(S)-Baclofen hydrochloride

2D chemical structure of 66514-99-6(S)-Baclofen

2D chemical structure of 1395997-58-6Acamprosate mixture with baclofen


Strategy for asymmetric synthesis of (R)-(-)-Baclofen is as represented in the Scheme 14. Herein, we made use of asymmetric Michael addition of nitromethane to 4- Chlorochalcone in the presence of Cu(acac)2 and (-)-Sparteine as a catalyst in DCM for 8 h to provide γ-nitro ketone as colorless solid, mp 105-109°C, in 87% yield with 82% ee. The Michael adduct 3d on Baeyer-Villiger reaction using m-CPBA to produce corresponding nitro ester 6a. The reduction of 6a containing nitro group can be reduced with sodium borohydride in presence of NiCl2. It resulted to generate 7 cyclic pyrrolidine moiety in 65% yield. Which upon hydrolysis with HCl will lead to (R)-(-)- Baclofen 8 as a neurotransmitter inhibitor drug molecule

(R)-4-amino-3-(4-chlorophenyl)butanoic acid hydrochloride (8) The solution of 7 (100 mg, 0.51 mmol) in 6N HCl (2.7 mL) was refluxed at 100 °C. After 24 h, the reaction mixture was concentrated in vacuo to afford (R)-(–)- Baclofen 8 as colorless solid 93 mg, in 73% yield. Yield : 73% State : Solid. M.P. : 188-189 °C [a]D 25 : –3.4o (c = 0.65, H2O), lit.7 –3.79o (c = 0.65, H2O, 99 % ee) 1 H-NMR (300MHz, D2O) : δ. 7.36-7.49 (m, 4H) 3.50-3.37 (m, 2H), 2.30-3.22 (m, 1H), 2.71-2.92 (dd, 2H,) J = 9.5, 16.5 Hz).ppm 13C-NMR (75MHz, D2O) : δ. 175.46, 138.28, 136.95, 133.32, 129.32, 128.25, 127.81, 43.75, 39.91, 38.18.

7. Corey, E. J; Zhang, F. Y. Org. Lett. 2000, 2, 4257-4259

16. a) Thakur, V. V.; Nikalje, M. D.; Sudalai, A. Tetrahedron Asymmetry 2003, 14, 581. b) Chenevert R.; Desjardins, M.; Tetrahedron Lett. 1991, 32, 4249. c) Herdeis, C.; Hubmann, H. P. Tetrahedron Asymmetry 1992, 3, 1213. d) Meyers, A. I.; Snyder, L. J. Org. Chem. 1993, 58, 36.

clip 2

Yoshiji Takemoto (2005)6 Yoshiji Takemoto et al. have developed chiral thiourea catalyst 15 which was found to be highly efficient for the asymmetric Michael addition of 1,3-dicarbonyl compound to nitroolefins. Furthermore, a new synthetic route for (R)-(-)-Baclofen 14 and the generation of a chiral quaternary carbon center with high enantioselectivity by Michael reaction were developed (Scheme 6)

6. Okino, T.; Hoashi, Y.; Xuenong Xu,; Takemoto, Y.. J. Am. Chem. Soc. 2005, 127, 119.


Enantio- and Diastereoselective Michael Reaction of 1,3-Dicarbonyl Compounds to Nitroolefins Catalyzed by a Bifunctional Thiourea

Contribution from the Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
J. Am. Chem. Soc.2005127 (1), pp 119–125
DOI: 10.1021/ja044370p
Publication Date (Web): December 3, 2004
Copyright © 2005 American Chemical Society


Abstract Image

We synthesized a new class of bifunctional catalysts bearing a thiourea moiety and an amino group on a chiral scaffold. Among them, thiourea 1e bearing 3,5-bis(trifluoromethyl)benzene and dimethylamino groups was revealed to be highly efficient for the asymmetric Michael reaction of 1,3-dicarbonyl compounds to nitroolefins. Furthermore, we have developed a new synthetic route for (R)-(−)-baclofen and a chiral quaternary carbon center with high enantioselectivity by Michael reaction. In these reactions, we assumed that a thiourea moiety and an amino group of the catalyst activates a nitroolefin and a 1,3-dicarbonyl compound, respectively, to afford the Michael adduct with high enantio- and diastereoselectivity.

Synthesis of (R)()-Baclofen. γ-Amino butylic acid (GABA) plays an important role as an inhibitory neurotransmitter in the central nervous system (CNS) of mammalians,20,21 and the deficiency of GABA is associated with diseases that exhibit neuromuscular dysfunctions such as epilespy, Huntington’s and Parkinson’s diseases, etc.22 Baclofen is a lipophilic analogue of GABA, and it is widely used as an antispastic agent. Although baclofen is commercialized in its racemic form, it has been reported that its biological activity resides exlusively in the (R)-enantiomer.23 We next applied our enantioselective Michael reaction for the synthesis of (R)-(−)-baclofen (Scheme 1). The reaction of 4-chlorobenzaldehyde with nitromethane and subsequent dehydration of the resultant alcohol provided nitroolefin 9, which was reacted with diethyl malonate 3a in the presence of 10 mol % of 1e to afford the adduct 10 in 80% yield with 94% ee. Furthermore, enantiomerically pure 10 (>99% ee) was obtained after single recrystallization from Hexane/EtOAc. Reduction of the nitro group with nickel borite and in situ lactonization gave lactone 11 in 94%. The ester group of 11 was hydrolyzed and decarboxylated to afford 12. The specific rotation of 12 was compared with that of literature data24 ([α]30D −39.7° (c 1.00, EtOH), lit. [α]25D −39.0° (c 1, EtOH)), and, as expected, the absolute configuration of 12 was determined to be R. Lactam 12 was finally hydrolyzed with 6N HCl, affording enantiomerically pure (R)-(−)-baclofen as its hydrochloric salt with 38% overall yield in six steps from 4-chlorobenzaldehyde. Consequently, we succeeded in the synthesis of (R)-(−)-baclofen by the simple procedure with high enantioselctivity.


Scheme 1.  Total Synthesis of (R)-(−)-Baclofena

a Conditions:  (a) MeNO2, NaOMe, MeOH, room temperature, 15 h; (b) MsCl, TEA, THF, room temperature, 1 h; (c) diethyl malonate, 1e, toluene, room temperature, 24 h; (d) NiCl2·6H2O, NaBH4, MeOH, room temperature, 7.5 h; (e) NaOH, EtOH, room temperature, 45 h; (f) toluene, reflux, 6.5 h; (g) 6N HCl, reflux, 24 h.

Total synthesis of (R)-(–)-baclofen. 9: The mixture of 4-chlorobenzaldehyde (1.41 g, 10 mmol), nitromethane (10 equiv, 5.4 ml) and NaOMe (0.10 equiv, 54.0 mg) in MeOH (10 ml) was stirred overnight. Saturated ammonium chloride was added to the mixture and aqueous phase was extracted with AcOEt. The extract was washed with brine, dried over MgSO4, filtrated and concentrated in vacuo. The residue was purified by by column chromatography on silica gel (Hexane/AcOEt = 3/1 as eluent) to afford desired nitroalcohol 8 (1.82 g, 90%). To the stirred solution of the obtained nitroalcohol 8 and MsCl (1.2 equiv, 0.84 ml) in THF (9.0 ml) was added TEA (2.1 equiv, 2.7 ml) dropwise at 0 °C. After 1 h, saturated ammonium chloride was added to the reaction mixture and aqueous phase was extracted with AcOEt. The extract was washed with 1N HCl (two times), saturated NaHCO3 and brine, dried over MgSO4, filtrated and concentrated in vacuo. The residual solid was purified by recrystallization from AcOEt/Hexane to afford the desired nitroolefin 9 (1.20 g, 72%). yellow needle; m.p. 112 °C (AcOEt/Hexane); 1 H NMR (500 MHz, CDCl3) δ 7.97 (d, J = 13.7 Hz, 1H), 7.57 (d, J = 13.7 Hz, 1H), 7.50 (d, J = 8.6 Hz, 2H), 7.44 (d, J = 8.6 Hz, 2H) ppm; 13 C NMR (126 MHz, CDCl3) δ 138.4, 137.7, 137.5, 130.3, 129.8, 128.6 ppm; IR (CHCl3) ν 3113, 3029, 1637, 1594, 1525, 1494 cm-1 ; MS (EI + ) 183 (M+ , 51), 101 (100); Anal. Calcd. for C8H6ClNO2: C 52.34; H, 3.29; N, 7.63; Cl, 19.31. Found: C, 52.35; H, 3.40; N, 7.67; Cl, 19.24. 10: Under argon atmosphere, to the stirred solution of p-chloro-β-nitrostylene 9 (36.7 mg, 0.20 mmol) and thiourea (0.10 equiv, 8.3 mg) in toluene (0.40 ml) was added diethylmalonate (2 equiv, 0.060 ml) at rt. After 24 h, the reaction mixture was concentrated in vacuo. The residue was purified by column chromatography on silica gel (AcOEt/hexane = 1/5 as eluent) to afford desired product 10 (55.3 mg, 80%) as colorless solid. Enantiomerically pure 10 (>99% ee) was obtained after single recrystallization from Hexane/AcOEt. m.p. 56-57 °C (Hexane/AcOEt); [α]D 25 –8.56 (c 1.02, CHCl3, >99% ee); 1 H NMR (500 MHz, CDCl3) δ 7.30 (d, J = 8.2 Hz, 2H), 7.19 (d, J = 8.6 Hz, 2H), 4.91 (dd, J = 4.6, 13.1 Hz, 1H), 4.83 (dd, J = 9.5, 13.1 Hz, 1H), 4.23 (m, 3H), 4.04 (q, J = 7.22 Hz, 2H), 3.78 (d, J = 9.5 Hz, 1H), 1.27 (t, J = 7.2 Hz, 3H), 1.09 (t, J = 7.0 Hz, 3H); 13 C NMR (126 MHz, CDCl3) δ 167.4, 166.8, 134.9, 134.5, 129.6, 129.3, 77.5, 62.3, 62.1, 54.8, 42.4, 14.0, 13.8 ppm; IR (CHCl3) ν 3031, 2994, 1733, 1558, 1494, 1374 cm-1 ; MS (FAB+ ) 344 (MH+ , 100); Anal. Calcd for C15H18ClNO6: C, 52.42, H, 5.28, N, 4.07, Cl, 10.31; Found: C, 52.52, H, 5.21, N, 4.07, Cl, 10.25; HPLC [Chiralcel OD-H, hexane/2-propannol = 90/10, 0.5 mL/min, λ = 210 nm, retention times: (major) 28.3 min, (minor) 25.1 min]. 11: Under argon atmosphere, to the suspension of 10 (550 mg, 1.60 mmol, >99% ee) and NiCl2· 6H2O (1.0 equiv, 380 mg) in MeOH (8.0 ml) was added NaBH4 (12 equiv, 726 mg) at 0 °C. After the reaction mixture was stirred 7.5 h at rt, the reaction mixture was quenched with NH4Cl and diluted with CHCl3. The organic layer was separated and dried over MgSO4, filtrated and concentrated in vacuo. The residue was purified by column chromatography on silica gel (MeOH/CHCl3 = 1/20 as eluent) to afford desired product (402 mg, 94%) as colorless powder. m.p. 126-128 °C (Hexane/AcOEt); [α]D 26 –123.4 (c 0.96, CHCl3); 1 H NMR (500 MHz, CDCl3) δ 7.31 (m, 2H), 7.20 (d, J = 8.2 Hz, 2H), 7.12 (s, 1H), 4.24 (q, J = 7.0 Hz, 1H), 4.09 (m, 1H), 3.81 (m, 2H), 3.54 (m, 1H), 3.41 (m, 1H), 1.28 (t, J = 6.9 Hz, 3H); 13 C NMR (126 MHz, CDCl3) δ 172.5, 169.0, 138.3, 133.5, 129.2, 128.4, 61.9, 55.2, 47.5, 43.7, 14.1 ppm; IR (CHCl3) ν 3435, 3229, 3017, 2360, 1710, 1493 cm-1 ; MS (FAB+ ) 268 (MH+ , 100); Anal. Calcd for C13H14ClNO3: C, 58.32, H, 5.27, N, 5.23, Cl, 13.24; Found: C, 58.10, H, 5.15, N, 5.43, Cl, 13.13. 12 : To the solution of 11 (240mg, 0.90 mmol) in EtOH (3.6 ml) was added 1N NaOH (1.1 ml) at rt. After 30 min, the reaction mixture was concerned in vacuo. To the residue was added H2O and 5N HCl, and the aqueous phase was extracted with CHCl3. The extract was dried over MgSO4, filtrated andconcentrated in vacuo to afford corresponding carboxylic acid (194 mg, 90%). The solution of carboxylic acid (194 mg, 0.81 mmol) in toluene (11 ml) was refluxed at 140 °C. After 6 h, the mixture was concentrated in vacuo. The residue was purified by column chromatography on silica gel (MeOH/ CHCl3 = 1/7) to afford desired product 12 (148 mg, 93%) as colorless needle. m.p. 109-111 °C (Hexane/AcOEt); [α]D 30 –39.7 (c 1.00, CHCl3); 1 H NMR (500 MHz, CDCl3) δ 7.32 (d, J = 7.9 Hz, 2H), 7.19 (t, J = 8.2 Hz, 2H), 6.15 (s, 1H), 3.79 (t, J = 8.9 Hz, 1H), 3.68 (m, 1H), 3.38 (t, J = 8.4 Hz, 1H), 2.74 (dd, J = 9.0, 16.9 Hz, 1H), 2.45 (dd, J = 8.6, 16.8 Hz, 1H); 13 C NMR (126 MHz, CDCl3) δ 177.5, 140.7, 132.9, 129.0, 128.1, 49.3, 39.6, 37.8 ppm; IR (CHCl3) ν 3439, 3006, 2361, 1699, 1494 cm-1 ; MS (FAB+ ) 196 (MH+ , 100); Anal. Calcd for C10H10ClNO: C, 61.39, H, 5.15, N, 7.16, Cl, 18.12; Found: C, 61.50, H, 5.21, N, 7.25, Cl, 17.98. (R)-(–)-baclofen : The solution of 12 (107 mg, 0.55 mmol) in 6N HCl (2.7 ml) was refluxed at 100 °C. After 24 h, the reaction mixture was concentrated in vacuo to afford (R)-(–)-baclofen (129 mg, 94%) as colorless solid. m.p. 188-189 °C (exane/i-PrOH); [α]D 25 –3.79 (c 0.65, H2O); 1 H NMR (500 MHz, DMSO-d6) δ 12.26 (s, 1H), 8.13 (s, 3H), 7.35 (m, 4H), 3.09 (m, 1H), 2.94 (m, 1H), 2.85 (dd, J = 5.5, 16.2 Hz, 1H), 2.56 (dd, J = 9.5, 16.5 Hz, 1H); 13 C NMR (126 MHz, DMSO-d6) δ 172.5, 139.5, 131.9, 130.0, 128.7, 128.6, 128.0, 43.1, 39.1, 37.8 ppm; MS (FAB+ ) 214 (MH+ , 100); HRMS (FAB+ ) Calcd for [C10H13ClNO2] + : 214.0635; Found: 214.0637.

Image result for baclofen synthesis

Image result for baclofen synthesis

Image result for baclofen synthesisThe thiourea catalyst L7 bearing 3,5-bis(trifluoromethyl) benzene and dimethylamino groups has been revealed to be efficient for the asymmetric Michael reaction of 1,3-dicarbonyl compounds to nitroolefins (Scheme 8). This methodology has been applied for the total synthesis of (R)-(−)-baclofen. Reaction of 4-chloronitrostyrene and 1,3-dicarbonyl compound generates quaternary carbon center with 94% ee. Reduction of the nitro gruop to amine and subsequent cyclization, esterification and ring opening provides ( R )-(−)-baclofen in 38% yield.

Image result for baclofen synthesis!divAbstract

Image result for baclofen synthesis!divAbstract

Image result for baclofen synthesis

Image result for baclofen synthesis


Highly enantioselective biotransformations of 2-aryl-4-pentenenitriles, a novel chemoenzymatic approach to (R)-(-)-baclofen
Tetrahedron Lett 2002, 43(37): 6617

Enantioselective Michael addition of nitromethane to alpha,beta-enones catalyzed by chiral quaternary ammoniun salts. A simple synthesis of (R)-baclofen
Org Lett 2000, 2(26): 4257

Stereospecific synthesis of (R)- and (S)-baclofen and (R)- and (S)-PCPGABA [4-amino-2-(4chlorophenyl)butyric Acid] via (R)- and (S)-3-(4-Chlorophenyl)pyrrolidines
Chem Pharm Bull 1995, 43(8): 1302

Enantioselective syntheses of (-)-(R)-rolipram, (-)-(R)-baclofen and other GABA analogues via rhodium-catalyzed conjugate addition of arylboronic acids
Synthesis (Stuttgart) 2003, (18): 2805

Palladium-catalyzed, asymmetric Baeyer-Villiger oxidation of prochiral cyclobutanones with PHOX ligands
Tetrahedron 2011, 67(24): 4352

An efficient synthesis of (R)- and (S)-baclofen via desymmetrization
Tetrahedron Lett 2009, 50(45): 6166

Recoverable resin-supported pyridylamide ligand for microwave-accelerated molybdenum-catalyzed asymmetric allylic alkylations: Enantioselective synthesis of baclofen
Org Lett 2003, 5(13): 2275

Asymmetric synthesis of ß-substituted ?-lactams via rhodium/diene-catalyzed 1,4-additions: Application to the synthesis of (R)-baclofen and (R)-rolipram
Org Lett 2011, 13(4): 788

Multisite organic-inorganic hybrid catalysts for the direct sustainable synthesis of GABAergic drugs
Angew Chem Int Ed 2014, 53(33): 8687


Image result for baclofen synthesis

Image result for baclofen synthesis

Image result for baclofen synthesis

Image result for baclofen synthesis

Image result for baclofen synthesis

(±)-Baclofen, hydrochloride (2)

A mixture of 4-(4-Chlorophenyl) pyrrolidin-2-one 15 (0.070 g, 0.35 mmol) in HCl aqueous solution (6 mol L-1, 1.5 cm3) was heated at 100 °C for 6 h. The solvent was removed under reduced pressure and the residue was triturated in isopropanol yielding a crystalline (±)-baclofen hydrochloride 2 (0.071 g, 82%).; IR nmax/cm -1: 3415, 3006, 1713, 1562, 1492, 1407, 1251, 1186, 815 cm-1 (KBr, neat); 1H NMR (300 MHz, CDCl3d 2.55 (dd, J 16.5 and 8.7 Hz, 1 H); 2.82 (dd, J 16.5 and 5.7 Hz, 1 H); 2.93-3.50 (m, 3 H); 7.34 (d, J 8.7 Hz, 2 H), 7.40 (d, J 8.7 Hz, 2 H), 7.94 (bs, 3H, NH3+), 12.23 (bs, 1 H, COOH), 13C NMR (CDCl3, 75 MHz) d 37.94, 39.70, 43.28, 128.89, 130.27, 132.20, 139.56, 172.71.

Title: Baclofen
CAS Registry Number: 1134-47-0
CAS Name: b-(Aminomethyl)-4-chlorobenzenepropanoic acid
Additional Names: b-(aminomethyl)-p-chlorohydrocinnamic acid; g-amino-b-(p-chlorophenyl)butyric acid; b-(4-chlorophenyl)GABA
Manufacturers’ Codes: Ba-34647
Trademarks: Baclon (Leiras); Clofen (Alphapharm); Lioresal (Novartis)
Molecular Formula: C10H12ClNO2
Molecular Weight: 213.66
Percent Composition: C 56.21%, H 5.66%, Cl 16.59%, N 6.56%, O 14.98%
Literature References: Specific GABA-B receptor agonist. Prepn: NL 6407755; H. Keberle et al., US 3471548 (1965, 1969 both to Ciba). Toxicity study: T. Tadokoro et al., Osaka Daigaku Igaku Zasshi 28, 265 (1976), C.A. 88, 183016u (1978). Comprehensive description: S. Ahuja, Anal. Profiles Drug Subs. 14, 527-548 (1985). Review of pharmacology and therapeutic efficacy in spasticity: R. N. Brogden et al., Drugs 8, 1-14 (1974); of intrathecal use in spinal cord injury: K. S. Lewis, W. M. Mueller, Ann. Pharmacother.27, 767-774 (1993). Clinical evaluation in reflex sympathetic dystrophy: B. J. van Hilten et al., N. Engl. J. Med. 343, 625 (2000).
Properties: Crystals from water, mp 206-208° (Keberle); 189-191°, (Uchimaru). LD50 in male mice, rats (mg/kg): 45, 78 i.v.; 103, 115 s.c.; 200, 145 orally (Tadokoro).
Melting point: mp 206-208° (Keberle); 189-191°, (Uchimaru)
Toxicity data: LD50 in male mice, rats (mg/kg): 45, 78 i.v.; 103, 115 s.c.; 200, 145 orally (Tadokoro)
Derivative Type: Hydrochloride
Molecular Formula: C10H13Cl2NO2
Molecular Weight: 250.12
Percent Composition: C 48.02%, H 5.24%, Cl 28.35%, N 5.60%, O 12.79%
Properties: mp 179-181°.
Melting point: mp 179-181°
Therap-Cat: Muscle relaxant (skeletal).
Keywords: Muscle Relaxant (Skeletal).

/////////////////(R)-(–)-Baclofen, Arbaclofen, STX 209, AGI 006, Spasticity,  PREREGISTERD, OSMOTICA PHARMA


(+)-(S,S)-Reboxetine succinate, Esreboxetine succinate

Image result for (S,S)-Reboxetine succinateimg

Esreboxetine succinate


(2S)-2-[(S)-(2-ethoxyphenoxy)(phenyl)methyl]morpholine butanedioate (1:1)
(2S)-2-[(S)-(2-Ethoxyphenoxy)(phenyl)methyl]morpholine succinate (1:1)
(S,S)-reboxetine succinate
635724-55-9 [RN]
Esreboxetine succinate [USAN]
Morpholine, 2-[(S)-(2-ethoxyphenoxy)phenylmethyl]-, (2S)-, butanedioate (1:1)
Succinic acid – (2S)-2-[(S)-(2-ethoxyphenoxy)(phenyl)methyl]morpholine (1:1)

Esreboxetine is a selective norepinephrine reuptake inhibitor which was under development by Pfizer for the treatment of neuropathic pain and fibromyalgia but failed to show significant benefit over currently available medications and was discontinued.[1][2][3][4] It is the (S,S)-(+)-enantiomer of reboxetine and is even more selective in comparison.[1][5]

However, recently it has been shown that esreboxetine could be effective in fibromyalgia patients.[6]


Reboxetine mesylate (1) and succinate (2).

Image result for (S,S)-Reboxetine succinate

Image result for (S,S)-Reboxetine succinate


The synthesis of (±)-reboxetine mesylate,4 the Active Pharmaceutical Ingredient (API) for Edronax™.

Scheme 1 The synthesis of (±)-reboxetine mesylate,4 the Active Pharmaceutical Ingredient (API) for Edronax™.


The conversion of (±)-reboxetine mesylate to (S,S)-reboxetine succinate.
Scheme 2 The conversion of (±)-reboxetine mesylate to (S,S)-reboxetine succinate.


The Pfizer early resolution route to (S,S)-reboxetine succinate.
Scheme 3 The Pfizer early resolution route to (S,S)-reboxetine succinate.

The Pfizer asymmetric synthesis for (S,S)-reboxetine intended for commercialisation.

Scheme 4 The Pfizer asymmetric synthesis for (S,S)-reboxetine intended for commercialisation.


(S,S)-Reboxetine succinate (3) (Figure 1) has been under late-stage development at Pfizer for the medication of neuropathic and fibromyalgia pain.(16)

16.(a) HughesB.McKenzieI.StokerM. J. WO2006/000903, May 1, 2006.

(b) AllenA. J.Hemrick-LueckeS.SumnerC. R.WallaceO. B. WO2005/060949, July 7, 2005.

(c) KelseyD. K. WO2005/021095, Oct 3, 2005.

(d) AllenA. J.KelseyD. K. WO 2005/020976, Oct 3, 2005.

(e) SumnerC. R. WO2005/020975, Oct 3, 2005.

(f) HassanF. WO2004/016272, Feb 26, 2004.

(g) WongE. H. F. WO2004/002463, Jan 8, 2004.


Process Development for (S,S)-Reboxetine Succinate via a Sharpless Asymmetric Epoxidation

Pfizer Global Research and Development, 2800 Plymouth Road, Ann Arbor, Michigan 48105, U.S.A.
Org. Process Res. Dev.200711 (3), pp 354–358
DOI: 10.1021/op700007g
Publication Date (Web): March 23, 2007
Copyright © 2007 American Chemical Society


Abstract Image

Reboxetine mesylate is a selective norepinephrine uptake inhibitor (NRI) currently marketed as the racemate. The (S,S)-enantiomer of reboxetine is being evaluated for the treatment of neuropathic pain and a variety of other indications. (S,S)-Reboxetine has usually been prepared by resolution of the racemate as the (−)-mandelate salt, an inherently inefficient process. A chiral synthesis starting with a Sharpless asymmetric epoxidation of cinnamyl alcohol to yield (R,R)-phenylglycidol was developed. (R,R)-Phenylglycidol was reacted without isolation with 2-ethoxyphenol to give 4, which was isolated by direct crystallization. Key process variables for the asymmetric epoxidation were investigated. Conversion of (R,S)-4 to reboxetine parallels the racemic synthesis with streamlined and optimized processing conditions. (S,S)-Reboxetine free base was converted directly to the succinate salt without isolation as the mesylate salt.

(2S,3S)-Reboxetine Succinate (9).

mp 145.2−147.1 °C (lit. mp 148 °C).8 1H NMR (400.13 MHz, CDCl3) δ 1.41 (t, J = 7.0 Hz, 3H), 2.4 (s, 4H), 2.9−3.06 (m, 2H), 3.15−3.22 (m, 2H), 3.81−3.86 (m, 1H), 4.02−4.09 (m, 3H), 4.17−4.24 (m, 1H), 5.13 (d, J = 4.3 Hz), 6.66−6.90 (m, 4H), 7.26−7.39 (m, 5H). 13C NMR (100.62 MHz, CDCl3) δ 15.08, 31.89, 43.24, 44.84, 64.72, 76.91, 82.91, 113.94, 118.27, 121.1, 127.38, 128.66, 136.94, 149.8, 178.73. LRMS-APCI m/z calcd for C19H23NO3 (M + H)+:  314. Found:  m/z = 314 [M + 1]+. Anal. Calcd for C19H23NO3−C4H6O4:  C, 64.02; H, 6.77; N, 3.25. Found:  C, 63.99; H, 6.77; N, 3.16. [α]32.4D +17.24° (c 0.5, EtOH).

8)Zampieri, M.; Airoldi, A.; Martini, A. WO2003/106441, 12/24/03.


Commercial Synthesis of (S,S)-Reboxetine Succinate: A Journey To Find the Cheapest Commercial Chemistry for Manufacture

Chemical Research and Development, Pfizer Inc., Sandwich Laboratories, Sandwich, Kent, CT13 9NJ, United Kingdom
Org. Process Res. Dev.201115 (6), pp 1305–1314
DOI: 10.1021/op200181f
Publication Date (Web): August 18, 2011
Copyright © 2011 American Chemical Society


Abstract Image

The development of a synthetic process for (S,S)-reboxetine succinate, a candidate for the treatment of fibromylagia, is disclosed from initial scale-up to deliver material for registrational stability testing through to commercial route evaluation and subsequent nomination. This entailed evaluation of several alternative routes to result in what would have been a commercially attractive process for launch of the compound.

(2S,3S)-2-[α-(2-Ethoxyphenoxy)benzyl]morpholine Succinate Salt (S,S)-Reboxetine Succinate

 (S,S)-reboxetine succinate (897 g, 82%) as a white solid. 1H NMR (400 MHz, d6-DMSO) δ 7.22–7.54 (m, 5H), 6.66–6.96 (m, 4H), 5.27 (d, J = 6.0 Hz, 1H), 4.01 (q, J = 7.1 Hz, 2H), 3.83 (m, 2H), 3.50 (m, 2H), 2.61–2.82 (m, 3H), 2.34 (br s, 4H), 1.33 (t, J = 7.1 Hz, 3H). 13C NMR (100 MHz, d6-DMSO) δ 174.4, 149.0, 147.3, 137.8, 128.2, 127.3, 120.7, 116.7, 114.4, 80.8, 77.5, 65.9, 64.1, 45.8, 44.1, 39.7, 39.


  1. Jump up to:a b Matilda Bingham; Napier, Susan Jolliffe (2009). Transporters as Targets for Drugs (Topics in Medicinal Chemistry). Berlin: Springer. ISBN 3-540-87911-0.
  2. Jump up^ Rao SG (October 2009). “Current progress in the pharmacological therapy of fibromyalgia”Expert Opinion on Investigational Drugs18 (10): 1479–93. PMID 19732029doi:10.1517/13543780903203771.
  3. Jump up^ “Search of: esreboxetine – List Results –”.
  4. Jump up^ “Musculoskeletal Report: Pfizer Stops Work on Esreboxetine for FM”.
  5. Jump up^ Fish, P. V.; MacKenny, M.; Bish, G.; Buxton, T.; Cave, R.; Drouard, D.; Hoople, D.; Jessiman, A.; Miller, D.; Pasquinet, C.; Patel, B.; Reeves, K.; Ryckmans, T.; Skerten, M.; Wakenhut, F. (2009). “Enantioselective synthesis of (R)- and (S)-N-Boc-morpholine-2-carboxylic acids by enzyme-catalyzed kinetic resolution: application to the synthesis of reboxetine analogs”. Tetrahedron Letters50 (4): 389. doi:10.1016/j.tetlet.2008.11.025.
  6. Jump up^ Arnold, L. M., Hirsch, I., Sanders, P., Ellis, A. and Hughes, B. (2012), Safety and efficacy of esreboxetine in patients with fibromyalgia: A fourteen-week, randomized, 


1: Fujimori I, Yukawa T, Kamei T, Nakada Y, Sakauchi N, Yamada M, Ohba Y, Takiguchi M, Kuno M, Kamo I, Nakagawa H, Hamada T, Igari T, Okuda T, Yamamoto S, Tsukamoto T, Ishichi Y, Ueno H. Design, synthesis and biological evaluation of a novel series of peripheral-selective noradrenaline reuptake inhibitor. Bioorg Med Chem. 2015 Aug 1;23(15):5000-14. doi: 10.1016/j.bmc.2015.05.017. Epub 2015 May 15. PubMed PMID: 26051602.

2: Shen F, Tsuruda PR, Smith JA, Obedencio GP, Martin WJ. Relative contributions of norepinephrine and serotonin transporters to antinociceptive synergy between monoamine reuptake inhibitors and morphine in the rat formalin model. PLoS One. 2013 Sep 30;8(9):e74891. doi: 10.1371/journal.pone.0074891. eCollection 2013. PubMed PMID: 24098676; PubMed Central PMCID: PMC3787017.

3: Arnold LM, Hirsch I, Sanders P, Ellis A, Hughes B. Safety and efficacy of esreboxetine in patients with fibromyalgia: a fourteen-week, randomized, double-blind, placebo-controlled, multicenter clinical trial. Arthritis Rheum. 2012 Jul;64(7):2387-97. doi: 10.1002/art.34390. PubMed PMID: 22275142.

4: Arnold LM, Chatamra K, Hirsch I, Stoker M. Safety and efficacy of esreboxetine in patients with fibromyalgia: An 8-week, multicenter, randomized, double-blind, placebo-controlled study. Clin Ther. 2010 Aug;32(9):1618-32. doi: 10.1016/j.clinthera.2010.08.003. PubMed PMID: 20974319.

5: Klarskov N, Scholfield D, Soma K, Darekar A, Mills I, Lose G. Measurement of urethral closure function in women with stress urinary incontinence. J Urol. 2009 Jun;181(6):2628-33; discussion 2633. doi: 10.1016/j.juro.2009.01.114. Epub 2009 Apr 16. PubMed PMID: 19375093.

Clinical data
Routes of
ATC code
  • None
Legal status
Legal status
  • In general: uncontrolled
CAS Number
PubChem CID
Chemical and physical data
Formula C19H23NO3
Molar mass 313.391 g/mol
3D model (JSmol)

////////////(+)-(S,S)-Reboxetine, (S,S)-Reboxetine, Reboxetine, Esreboxetine succinate


ESCITALOPRAM, S-(+)-Citalopram, эсциталопрам , إيسكيتالوبرام , 艾司西酞普兰 ,

ChemSpider 2D Image | Escitalopram | C20H21FN2OImage result for ESCITALOPRAM
(1S)-1-[3-(Dimethylamino)propyl]-1-(4-fluorophenyl)-1,3-dihydro-2-benzofuran-5-carbonitrile [ACD/IUPAC Name]
128196-01-0 [RN]
5-Isobenzofurancarbonitrile, 1-[3-(dimethylamino)propyl]-1-(4-fluorophenyl)-1,3-dihydro-, (1S)- [ACD/Index Name]
  • Molecular FormulaC20H21FN2O
  • Average mass324.392 Da
  • S-(+)-Citalopram
    эсциталопрам [Russian] [INN]
    إيسكيتالوبرام [Arabic] [INN]
    艾司西酞普兰 [Chinese] [INN]

Image result for ESCITALOPRAM

Lexapro® (escitalopram oxalate) is an orally administered selective serotonin reuptake inhibitor (SSRI). Escitalopram is the pure Senantiomer (single isomer) of the racemic bicyclic phthalane derivative citalopram. Escitalopram oxalate is designated S-(+)-1-[3(dimethyl-amino)propyl]-1-(p-fluorophenyl)-5-phthalancarbonitrile oxalate with the following structural formula:


Lexapro® (escitalopram oxalate) Structural Formual Illustration

The molecular formula is C20H21FN2O • C2H2O4 and the molecular weight is 414.40.

Escitalopram oxalate occurs as a fine, white to slightly-yellow powder and is freely soluble in methanol and dimethyl sulfoxide (DMSO), soluble in isotonic saline solution, sparingly soluble in water and ethanol, slightly soluble in ethyl acetate, and insoluble in heptane.

Lexapro (escitalopram oxalate) is available as tablets or as an oral solution.

Lexapro tablets are film-coated, round tablets containing escitalopram oxalate in strengths equivalent to 5 mg, 10 mg, and 20 mg escitalopram base. The 10 and 20 mg tablets are scored. The tablets also contain the following inactive ingredients: talc, croscarmellose sodium, microcrystalline cellulose/colloidal silicon dioxide, and magnesium stearate. The film coating contains hypromellose, titanium dioxide, and polyethylene glycol.

Lexapro oral solution contains escitalopram oxalate equivalent to 1 mg/mL escitalopram base. It also contains the following inactive ingredients: sorbitol, purified water, citric acid, sodium citrate, malic acid, glycerin, propylene glycol, methylparaben, propylparaben, and natural peppermint flavor.

Escitalopram, also known by the brand names Lexapro and Cipralex among others, is an antidepressant of the selective serotonin reuptake inhibitor (SSRI) class. It is approved by the U.S. Food and Drug Administration (FDA) for the treatment of adults and children over 12 years of age with major depressive disorder (MDD) or generalized anxiety disorder (GAD). Escitalopram is the (S)-stereoisomer(Left-enantiomer) of the earlier Lundbeck drug citalopram, hence the name escitalopram. Whether escitalopram exhibits superior therapeutic properties to citalopram or merely represents an example of “evergreening” is controversial.[2]

Medical uses

Escitalopram has FDA approval for the treatment of major depressive disorder in adolescents and adults, and generalized anxiety disorder in adults.[3] In European countries and Australia, it is approved for depression (MDD) and certain anxiety disorders: general anxiety disorder (GAD), social anxiety disorder (SAD), obsessive-compulsive disorder (OCD), and panic disorder with or without agoraphobia.


Escitalopram was approved by regulatory authorities for the treatment of major depressive disorder on the basis of four placebo controlled, double-blind trials, three of which demonstrated a statistical superiority over placebo.[4]

Controversy exists regarding the effectiveness of escitalopram compared to its predecessor citalopram. The importance of this issue follows from the greater cost of escitalopram relative to the generic mixture of isomers citalopram prior to the expiration of the escitalopram patent in 2012, which led to charges of evergreening. Accordingly, this issue has been examined in at least 10 different systematic reviews and meta analyses. The most recent of these have concluded (with caveats in some cases) that escitalopram is modestly superior to citalopram in efficacy and tolerability.[5][6][7][8]

In contrast to these findings, a 2011 review concluded that all second-generation antidepressants are equally effective,[9] and treatment guidelines issued by the National Institute of Health and Clinical Excellence and by the American Psychiatric Association generally reflect this viewpoint.[10][11]

Anxiety disorder

Escitalopram appears to be effective in treating general anxiety disorder, with relapse on escitalopram (20%) less than placebo (50%).[12]


Escitalopram as well as other SSRIs are effective in reducing the symptoms of premenstrual syndrome, whether taken in the luteal phase only or continuously.[13] There is no good data available for escitalopram for seasonal affective disorder as of 2011.[14] SSRIs do not appear to be useful for preventing tension headaches or migraines.[15][16]

Adverse effects

Escitalopram, like other SSRIs, has been shown to affect sexual functions causing side effects such as decreased libidodelayed ejaculation, genital anesthesia,[17] and anorgasmia.[18][19]

An analysis conducted by the FDA found a statistically insignificant 1.5 to 2.4-fold (depending on the statistical technique used) increase of suicidality among the adults treated with escitalopram for psychiatric indications.[20][21][22] The authors of a related study note the general problem with statistical approaches: due to the rarity of suicidal events in clinical trials, it is hard to draw firm conclusions with a sample smaller than two million patients.[23]

Escitalopram is not associated with significant weight gain. For example, 0.6 kg mean weight change after 6 months of treatment with escitalopram for depression was insignificant and similar to that with placebo (0.2 kg).[24] 1.4–1.8 kg mean weight gain was reported in 8-month trials of escitalopram for depression,[25] and generalized anxiety disorder.[26] A 52-week trial of escitalopram for the long-term treatment of depression in elderly also found insignificant 0.6 kg mean weight gain.[27] Escitalopram may help reduce weight in those treated for binge eating associated obesity.[28]

Citalopram and escitalopram are associated with dose-dependent QT interval prolongation[29] and should not be used in those with congenital long QT syndrome or known pre-existing QT interval prolongation, or in combination with other medicines that prolong the QT interval. ECG measurements should be considered for patients with cardiac disease, and electrolyte disturbances should be corrected before starting treatment. In December 2011, the UK implemented new restrictions on the maximum daily doses.[30][31] The U.S. Food and Drug Administration and Health Canada did not similarly order restrictions on escitalopram dosage, only on its predecessor citalopram.[32]

Escitalopram should be taken with caution when using Saint John’s wort.[33] Exposure to escitalopram is increased moderately, by about 50%, when it is taken with omeprazole. The authors of this study suggested that this increase is unlikely to be of clinical concern.[34] Caution should be used when taking cough medicine containing dextromethorphan (DXM) as serotonin syndrome, liver damage, and other negative side effects have been reported.

Discontinuation symptoms

Escitalopram discontinuation, particularly abruptly, may cause certain withdrawal symptoms such as “electric shock” sensations[35] (also known as “brain shivers” or “brain zaps”), dizziness, acute depressions and irritability, as well as heightened senses of akathisia.[36]


There is a tentative association of SSRI use during pregnancy with heart problems in the baby.[37] Their use during pregnancy should thus be balanced against that of depression.[37]


Excessive doses of escitalopram usually cause relatively minor untoward effects such as agitation and tachycardia. However, dyskinesiahypertonia, and clonus may occur in some cases. Plasma escitalopram concentrations are usually in a range of 20–80 μg/L in therapeutic situations and may reach 80–200 μg/L in the elderly, patients with hepatic dysfunction, those who are poor CYP2C19 metabolizers or following acute overdose. Monitoring of the drug in plasma or serum is generally accomplished using chromatographic methods. Chiral techniques are available to distinguish escitalopram from its racemate, citalopram.[38][39][40] Escitalopram seems to be less dangerous than citalopram in overdose and comparable to other SSRIs.[41]


Mechanism of action

Binding profile[42]
Receptor Ki (nM)
SERT 2.5
NET 6,514
5-HT2C 2,531
α1 3,870
M1 1,242
H1 1,973

Escitalopram increases intrasynaptic levels of the neurotransmitter serotonin by blocking the reuptake of the neurotransmitter into the presynaptic neuron. Of the SSRIs currently on the market, escitalopram has the highest selectivity for the serotonin transporter (SERT) compared to the norepinephrine transporter (NET), making the side-effect profile relatively mild in comparison to less-selective SSRIs.[43] The opposite enantiomer, (R)-citalopram, counteracts to a certain degree the serotonin-enhancing action of escitalopram.[citation needed] As a result, escitalopram has been claimed to be a more potent antidepressant than the racemic mixture, citalopram, of the two enantiomers. In order to explain this phenomenon, researchers from Lundbeck proposed that escitalopram enhances its own binding via an additional interaction with another allosteric site on the transporter.[44] Further research by the same group showed that (R)-citalopram also enhances binding of escitalopram,[45] and therefore the allosteric interaction cannot explain the observed counteracting effect. In the most recent paper, however, the same authors again reversed their findings and reported that (R)-citalopram decreases binding of escitalopram to the transporter.[46] Although allosteric binding of escitalopram to the serotonin transporter is of unquestionable research interest, its clinical relevance is unclear since the binding of escitalopram to the allosteric site is at least 1000 times weaker than to the primary binding site.

Escitalopram is a substrate of P-glycoprotein and hence P-glycoprotein inhibitors such as verapamil and quinidine may improve its blood-brain penetrability.[47] In a preclinical study in rats combining escitalopram with a P-glycoprotein inhibitor enhanced its antidepressant-like effects.[47]


Escitalopram, similarly to other SSRIs (with the exception of fluvoxamine), inhibits CYP2D6 and hence may increase plasma levels of a number of CYP2D6 substrates such as aripiprazolerisperidonetramadolcodeine, etc. As much of the effect of codeine is attributable to its conversion (10%) to morphine its effectiveness will be reduced by this inhibition, not enhanced.[48] As escitalopram is only a weak inhibitor of CYP2D6, analgesia from tramadol may not be affected.[49] Escitalopram can also prolong the QT interval and hence it is not recommended in patients that are concurrently on other medications that have the ability to prolong the QT interval. Being a SSRI, escitalopram should not be given concurrently with MAOIs or other serotonergic medications.[43]


Cipralex brand escitalopram 10mg package and tablet sheet

Escitalopram was developed in close cooperation between Lundbeck and Forest Laboratories. Its development was initiated in the summer of 1997, and the resulting new drug application was submitted to the U.S. FDA in March 2001. The short time (3.5 years) it took to develop escitalopram can be attributed to the previous extensive experience of Lundbeck and Forest with citalopram, which has similar pharmacology.[50] The FDA issued the approval of escitalopram for major depression in August 2002 and for generalized anxiety disorder in December 2003. On May 23, 2006, the FDA approved a generic version of escitalopram by Teva.[51] On July 14 of that year, however, the U.S. District Court of Delaware decided in favor of Lundbeck regarding the patent infringement dispute and ruled the patent on escitalopram valid.[52]

In 2006 Forest Laboratories was granted an 828-day (2 years and 3 months) extension on its US patent for escitalopram.[53] This pushed the patent expiration date from December 7, 2009 to September 14, 2011. Together with the 6-month pediatric exclusivity, the final expiration date was March 14, 2012.

Society and culture

Allegations of illegal marketing

In 2004, two separate civil suits alleging illegal marketing of citalopram and escitalopram for use by children and teenagers by Forest were initiated by two whistleblowers, one by a practicing physician named Joseph Piacentile, and the other by a Forest salesman named Christopher Gobble.[54] In February 2009, these two suits received support from the US Attorney for Massachusetts and were combined into one. Eleven states and the District of Columbia have also filed notices of intention to intervene as plaintiffs in the action. The suits allege that Forest illegally engaged in off-label promoting of Lexapro for use in children, that the company hid the results of a study showing lack of effectiveness in children, and that the company paid kickbacks to doctors to induce them to prescribe Lexapro to children. It was also alleged that the company conducted so-called “seeding studies” that were, in reality, marketing efforts to promote the drug’s use by doctors.[55][56] Forest responded to these allegations that it “is committed to adhering to the highest ethical and legal standards, and off-label promotion and improper payments to medical providers have consistently been against Forest policy.”[57] In 2010 Forest Pharmaceuticals Inc., agreed to pay more than $313 million to settle the charges over Lexapro and two other drugs, Levothroid and Celexa.[58]

Brand names

Escitalopram is sold under many brand names worldwide such as Cipralex.[1]


The Grignard condensation of 5-cyanophthalide (I) with 4-fluorophenylmagnesium bromide (II) in THF gives 1-(4-fluorophenyl)-1-hydroxy-1,3-dihydroisobenzofuran-5-carbonitrile bromomagnesium salt (III), which slowly rearranges to the benzophenone (IV). A new Grignard condensation of (IV) with 3-(dimethylamino)propylmagnesium chloride (V) in THF affords the expected bis(magnesium) salt (VI), which is hydrolyzed with acetic acid to provide the diol (VII) as a racemic mixture. Selective esterification of the primary alcohol of (VII) with (+)-3,3,3-trifluoro-2-methoxy-2-phenylacetyl chloride (VIII) gives the monoester (IX) as a mixture of diastereomers. This mixture is separated by HPLC and the desired diastereomer (X) is treated with potassium tert-butoxide in toluene.

A new method for the preparation of citalopram has been developed: The chlorination of 1-oxo-1,3-dihydroisobenzofuran-5-carboxylic acid (I) with refluxing SOCl2 gives the acyl chloride (II), which is condensed with 2-amino-2-methyl-1-propanol (III) in THF yielding the corresponding amide (IV). The cyclization of (IV) by means of SOCl2 affords the oxazoline (V), which is treated with 4-fluorophenylmagnesium bromide (VI) in THF giving the benzophenone (VII). This compound (VII), without isolation, is treated with 3-(dimethylamino)propylmagnesium chloride (VIII) in the same solvent, providing the cabinol (IX), which is cyclized by means of methanesulfonyl chloride and Et3N in CH2Cl2 yielding the isobenzofuran (X). Finally, this compound is treated with POCl3 in refluxing pyridine to generate the 5-cyano substituent of citalopram.

The chlorination of 1-oxo-1,3-dihydroisobenzofuran-5-carboxylic acid (XII) with refluxing SOCl2 gives the acyl chloride (XIII), which is condensed with 2-amino-2-methyl-1-propanol (XIV) in THF to yield the corresponding amide (XV). The cyclization of (XV) by means of SOCl2 affords the oxazoline (XVI), which is treated with 4-fluorophenylmagnesium bromide (XVII) in THF to give the benzophenone (XVIII). This compound (XVIII), without isolation, is treated with 3-(dimethylamino)propylmagnesium chloride (XIX) in the same solvent to provide the carbinol (XX), which is submitted to optical resolution with (+)- or (-)-tartaric acid, or (+)- or (-)-camphor-10-sulfonic acid (CSA) to give the desired (S)-enantiomer (XXI). Cyclization of (XXI) by means of methanesulfonyl chloride and TEA in dichloromethane yields the chiral isobenzofuran (XXII), which is finally treated with POCl3 in refluxing pyridine.

The Grignard condensation of 5-cyanophthalide (I) with 4-fluorophenylmagnesium bromide (II) in THF gives 1-(4-fluorophenyl)-1-hydroxy-1,3-dihydroisobenzofuran-5-carbonitrile bromomagnesium salt (III), which slowly rearranges to the benzophenone (IV). A new Grignard condensation of (IV) with 3-(dimethylamino)propylmagnesium chloride (V) in THF affords the expected bis(magnesium) salt (VI), which is hydrolyzed with acetic acid to provide the diol (VII) as a racemic mixture. Selective esterification of the primary alcohol of (VII) with (+)-3,3,3-trifluoro-2-methoxy-2-phenylacetyl chloride (VIII) gives the monoester (IX) as a mixture of diastereomers. This mixture is separated by HPLC and the desired diastereomer (X) is treated with potassium tert-butoxide in toluene

The Grignard condensation of 5-cyanophthalide (I) with 4-fluorophenylmagnesium bromide (II) in THF gives 1-(4-fluorophenyl)-1-hydroxy-1,3-dihydroisobenzofuran-5-carbonitrile bromomagnesium salt (III), which slowly rearranges to the benzophenone (IV). A new Grignard condensation of (IV) with 3-(dimethylamino)propylmagnesium chloride (V) in THF affords the expected bis(magnesium) salt (VI), which is hydrolyzed with acetic acid to provide the diol (VII) as a racemic mixture. Selective esterification of the primary alcohol of (VII) with (+)-3,3,3-trifluoro-2-methoxy-2-phenylacetyl chloride (VIII) gives the monoester (IX) as a mixture of diastereomers. This mixture is separated by HPLC and the desired diastereomer (X) is treated with potassium tert-butoxide in toluene.

Racemic 5-bromo-1-[3-(dimethylamino)propyl]-1-(4-fluorophenyl)-1,3-dihydroisobenzofuran (I) is submitted to optical resolution by chiral chromatography to give the corresponding (S)-isomer (II), which is treated with Zn(CN)2 and Pd(PPh3)4 to afford the target Escitalopram.

The esterification of racemic 1-[4-bromo-2-(hydroxymethyl)phenyl]-4-(dimethylamino)-1-(4-fluorophenyl)-1-butanol (I) with (S)-2-(6-methoxynaphth-2-yl)propionyl chloride (II) by means of TEA and DMAP in THF gives the corresponding ester (III) as a diastereomeric mixture that is separated by chiral chromatography over Daicel AD, the desired diastereomer (IV) is easily isolated. Finally, this ester is hydrolyzed and simultaneously cyclized by means of NaH in DMF to provide the target intermediate (V). Other acyl chlorides such as (S)-2-(4-isobutylphenyl)propionyl chloride, (S)-O-acetylmandeloyl chloride, (S)-benzyloxycarbonylprolyl chloride, (S)-2-phenylbutyryl chloride, (S)-2-methoxy-2-phenylacetyl chloride or (S)-N-acetylalanine can also be used in the preceding sequence.

Title: Citalopram
CAS Registry Number: 59729-33-8
CAS Name: 1-[3-(Dimethylamino)propyl]-1-(4-fluorophenyl)-1,3-dihydro-5-isobenzofurancarbonitrile
Additional Names: 1-[3-(dimethylamino)propyl]-1-(4-fluorophenyl)-5-phthalancarbonitrile; nitalapram
Manufacturers’ Codes: Lu-10-171
Molecular Formula: C20H21FN2O
Molecular Weight: 324.39
Percent Composition: C 74.05%, H 6.53%, F 5.86%, N 8.64%, O 4.93%
Literature References: Selective serotonin reuptake inhibitor (SSRI). Prepn: K. P. Boegesoe, A. S. Toft, DE 2657013eidem, US4136193 (1977, 1979 both to Kefalas); A. J. Bigler et al., Eur. J. Med. Chem. – Chim. Ther. 12, 289 (1977). Prepn of enantiomers: K. P. Boegesoe, J. Perregaard, EP 347066eidemUS 4943590, reissued as US RE 34712 (1989, 1990, 1994 all to Lundbeck). Pharmacology: A. V. Christensen et al., Eur. J. Pharmacol. 41, 153 (1977). HPLC determn in plasma and urine: E. Oyehaug et al.,J. Chromatogr. 308, 199 (1984). Comparative biotransformation of enantiomers: L. L. Von Moltke et al., Drug Metab. Dispos. 29, 1102 (2001). Review of clinical pharmacokinetics: K. Brosen, C. A. Naranjo, Eur. Neuropsychopharmacol. 11, 275-283 (2001). Review of clinical experience in depression: M. B. Keller, J. Clin. Psychiatry 61, 896-908 (2000). Clinical trial of S-form in depression: W. J. Burke et al, ibid63, 331 (2002).
Properties: bp0.03 175-181°.
Boiling point: bp0.03 175-181°
Derivative Type: Hydrobromide
CAS Registry Number: 59729-32-7
Trademarks: Celexa (Forest); Cipramil (Lundbeck); Elopram (Recordati); Seropram (Lundbeck)
Molecular Formula: C20H21FN2O.HBr
Molecular Weight: 405.30
Percent Composition: C 59.27%, H 5.47%, F 4.69%, N 6.91%, O 3.95%, Br 19.71%
Properties: Crystals from isopropanol, mp 182-183°.
Melting point: mp 182-183°
Derivative Type: S-(+)-Form
CAS Registry Number: 128196-01-0
Additional Names: Escitalopram
Properties: [a]D +12.33° (c = 1 in methanol).
Optical Rotation: [a]D +12.33° (c = 1 in methanol)
Derivative Type: Escitalopram oxalate
CAS Registry Number: 219861-08-2
Manufacturers’ Codes: Lu-26-054-0
Trademarks: Cipralex (Lundbeck); Gaudium (Recordati); Lexapro (Forest)
Molecular Formula: C20H21FN2O.C2H2O4
Molecular Weight: 414.43
Percent Composition: C 63.76%, H 5.59%, F 4.58%, N 6.76%, O 19.30%
Properties: Fine white to slightly yellow powder. Crystals from acetone, mp 147-148°. [a]D +12.31° (c = 1 in methanol). Freely sol in methanol, DMSO; sol in isotonic saline; sparingly sol in water, ethanol; slightly sol in ethyl acetate. Insol in heptane.
Melting point: mp 147-148°
Optical Rotation: [a]D +12.31° (c = 1 in methanol)
Therap-Cat: Antidepressant.
Keywords: Antidepressant; Bicyclics; Serotonin Uptake Inhibitor.


  1. Jump up to:a b international: Escitalopram Page accessed April 25, 2015
  2. Jump up^ NHS pays millions of pounds more than it needs to for drugsThe Independent. Retrieved 05/10/2011.
  3. Jump up^ “Escitalopram Oxalate”. The American Society of Health-System Pharmacists. Retrieved 3 April 2011.
  4. Jump up^ “” (PDF).
  5. Jump up^ Ramsberg J, Asseburg C, Henriksson M (2012). “Effectiveness and cost-effectiveness of antidepressants in primary care: a multiple treatment comparison meta-analysis and cost-effectiveness model”PLoS ONE7 (8): e42003. PMC 3410906Freely accessiblePMID 22876296doi:10.1371/journal.pone.0042003.
  6. Jump up^ Cipriani A, Purgato M, Furukawa TA, Trespidi C, Imperadore G, Signoretti A, Churchill R, Watanabe N, Barbui C (2012). “Citalopram versus other anti-depressive agents for depression”Cochrane Database Syst Rev7: CD006534. PMC 4204633Freely accessiblePMID 22786497doi:10.1002/14651858.CD006534.pub2.
  7. Jump up^ Favré P (February 2012). “[Clinical efficacy and achievement of a complete remission in depression: increasing interest in treatment with escitalopram]”. Encephale (in French). 38(1): 86–96. PMID 22381728doi:10.1016/j.encep.2011.11.003.
  8. Jump up^ Sicras-Mainar A, Navarro-Artieda R, Blanca-Tamayo M, Gimeno-de la Fuente V, Salvatella-Pasant J (December 2010). “Comparison of escitalopram vs. citalopram and venlafaxine in the treatment of major depression in Spain: clinical and economic consequences”. Curr Med Res Opin26 (12): 2757–64. PMID 21034375doi:10.1185/03007995.2010.529430.
  9. Jump up^ Gartlehner G, Hansen RA, Morgan LC, Thaler K, Lux L, Van Noord M, Mager U, Thieda P, Gaynes BN, Wilkins T, Strobelberger M, Lloyd S, Reichenpfader U, Lohr KN (Dec 6, 2011). “Comparative benefits and harms of second-generation antidepressants for treating major depressive disorder: an updated meta-analysis.”. Annals of Internal Medicine155 (11): 772–85. PMID 22147715doi:10.7326/0003-4819-155-11-201112060-00009.
  10. Jump up^ “CG90 Depression in adults: full guidance”.
  11. Jump up^ “PsychiatryOnline | APA Practice Guidelines | Practice Guideline for the Treatment of Patients With Major Depressive Disorder, Third Edition”.[permanent dead link]
  12. Jump up^ Bech P, Lönn SL, Overø KF (2010). “Relapse prevention and residual symptoms: a closer analysis of placebo-controlled continuation studies with escitalopram in major depressive disorder, generalized anxiety disorder, social anxiety disorder, and obsessive-compulsive disorder”. J Clin Psychiatry71 (2): 121–9. PMID 19961809doi:10.4088/JCP.08m04749blu.
  13. Jump up^ Marjoribanks J, Brown J, O’Brien PM, Wyatt K (Jun 7, 2013). “Selective serotonin reuptake inhibitors for premenstrual syndrome.”. The Cochrane database of systematic reviews6: CD001396. PMID 23744611doi:10.1002/14651858.CD001396.pub3.
  14. Jump up^ Thaler K, Delivuk M, Chapman A, Gaynes BN, Kaminski A, Gartlehner G (Dec 7, 2011). “Second-generation antidepressants for seasonal affective disorder.”. The Cochrane database of systematic reviews (12): CD008591. PMID 22161433doi:10.1002/14651858.CD008591.pub2.
  15. Jump up^ Banzi, R; Cusi, C; Randazzo, C; Sterzi, R; Tedesco, D; Moja, L (1 May 2015). “Selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) for the prevention of tension-type headache in adults.”. The Cochrane database of systematic reviews5: CD011681. PMID 25931277doi:10.1002/14651858.CD011681.
  16. Jump up^ Moja, PL; Cusi, C; Sterzi, RR; Canepari, C (20 July 2005). “Selective serotonin re-uptake inhibitors (SSRIs) for preventing migraine and tension-type headaches.”. The Cochrane database of systematic reviews (3): CD002919. PMID 16034880doi:10.1002/14651858.CD002919.pub2.
  17. Jump up^ Bolton JM, Sareen J, Reiss JP (2006). “Genital anesthesia persisting six years after sertraline discontinuation”. J Sex Marital Ther32 (4): 327–30. PMID 16709553doi:10.1080/00926230600666410.
  18. Jump up^ Clayton A, Keller A, McGarvey EL (2006). “Burden of phase-specific sexual dysfunction with SSRIs”. Journal of Affective Disorders91 (1): 27–32. PMID 16430968doi:10.1016/j.jad.2005.12.007.
  19. Jump up^ “Lexapro prescribing information” (PDF).
  20. Jump up^ Levenson M, Holland C. “Antidepressants and Suicidality in Adults: Statistical Evaluation. (Presentation at Psychopharmacologic Drugs Advisory Committee; December 13, 2006)”. Retrieved 2007-05-13.
  21. Jump up^ Stone MB, Jones ML (2006-11-17). “Clinical Review: Relationship Between Antidepressant Drugs and Suicidality in Adults” (PDF). Overview for December 13 Meeting of Pharmacological Drugs Advisory Committee (PDAC). FDA. pp. 11–74. Retrieved 2007-09-22.
  22. Jump up^ Levenson M; Holland C (2006-11-17). “Statistical Evaluation of Suicidality in Adults Treated with Antidepressants” (PDF). Overview for December 13 Meeting of Pharmacological Drugs Advisory Committee (PDAC). FDA. pp. 75–140. Retrieved 2007-09-22.
  23. Jump up^ Khan A, Schwartz K (2007). “Suicide risk and symptom reduction in patients assigned to placebo in duloxetine and escitalopram clinical trials: analysis of the FDA summary basis of approval reports”. Ann Clin Psychiatry19 (1): 31–6. PMID 17453659doi:10.1080/10401230601163550.
  24. Jump up^ Baldwin DS, Reines EH, Guiton C, Weiller E (2007). “Escitalopram therapy for major depression and anxiety disorders”. Ann Pharmacother41 (10): 1583–92. PMID 17848424doi:10.1345/aph.1K089.
  25. Jump up^ Pigott TA, Prakash A, Arnold LM, Aaronson ST, Mallinckrodt CH, Wohlreich MM (2007). “Duloxetine versus escitalopram and placebo: an 8-month, double-blind trial in patients with major depressive disorder”. Curr Med Res Opin23 (6): 1303–18. PMID 17559729doi:10.1185/030079907X188107.
  26. Jump up^ Davidson JR, Bose A, Wang Q (2005). “Safety and efficacy of escitalopram in the long-term treatment of generalized anxiety disorder”. J Clin Psychiatry66 (11): 1441–6. PMID 16420082doi:10.4088/JCP.v66n1115.
  27. Jump up^ Kasper S, Lemming OM, de Swart H (2006). “Escitalopram in the long-term treatment of major depressive disorder in elderly patients”. Neuropsychobiology54 (3): 152–9. PMID 17230032doi:10.1159/000098650.
  28. Jump up^ Guerdjikova AI, McElroy SL, Kotwal R, Welge JA, Nelson E, Lake K, Alessio DD, Keck PE, Hudson JI (January 2008). “High-dose escitalopram in the treatment of binge-eating disorder with obesity: a placebo-controlled monotherapy trial”. Human Psychopharmacology: Clinical and Experimental23 (1): 1–11. PMID 18058852doi:10.1002/hup.899.
  29. Jump up^ Castro VM, Clements CC, Murphy SN, Gainer VS, Fava M, Weilburg JB, Erb JL, Churchill SE, Kohane IS, Iosifescu DV, Smoller JW, Perlis RH (2013). “QT interval and antidepressant use: a cross sectional study of electronic health records”BMJ346: f288. PMC 3558546Freely accessiblePMID 23360890doi:10.1136/bmj.f288.
  30. Jump up^ “Citalopram and escitalopram: QT interval prolongation—new maximum daily dose restrictions (including in elderly patients), contraindications, and warnings”Medicines and Healthcare products Regulatory Agency. December 2011. Retrieved March 5, 2013.
  31. Jump up^ van Gorp F, Whyte IM, Isbister GK (2009). “Clinical and ECG Effects of Escitalopram Overdose” (PDF). Annals of Emergency Medicine54 (3): 404–8. PMID 19556032doi:10.1016/j.annemergmed.2009.04.016.
  32. Jump up^ Hasnain M, Howland RH, Vieweg WV (2013). “Escitalopram and QTc prolongation”J Psychiatry Neurosci38 (4): E11. PMC 3692726Freely accessibledoi:10.1503/jpn.130055.
  33. Jump up^ Karch, Amy (2006). 2006 Lippincott’s Nursing Drug Guide. Philadelphia, Baltimore, New York, London, Buenos Aires, Hong Kong, Sydney, Tokyo: Lippincott Williams & Wilkins. ISBN 1-58255-436-6.
  34. Jump up^ Malling D, Poulsen MN, Søgaard B (2005). “The effect of cimetidine or omeprazole on the pharmacokinetics of escitalopram in healthy subjects”British Journal of Clinical Pharmacology60 (3): 287–290. PMC 1884771Freely accessiblePMID 16120067doi:10.1111/j.1365-2125.2005.02423.x.
  35. Jump up^ Prakash O, Dhar V (2008). “Emergence of electric shock-like sensations on escitalopram discontinuation”. J Clin Psychopharmacol28 (3): 359–60. PMID 18480703doi:10.1097/JCP.0b013e3181727534.
  36. Jump up^ “Lexapro (Escitalopram Oxalate) Drug Information: Warnings and Precautions – Prescribing Information at RxList”. Retrieved 2015-08-09.
  37. Jump up to:a b Gentile, S (1 July 2015). “Early pregnancy exposure to selective serotonin reuptake inhibitors, risks of major structural malformations, and hypothesized teratogenic mechanisms.”. Expert opinion on drug metabolism & toxicology11: 1–13. PMID 26135630doi:10.1517/17425255.2015.1063614.
  38. Jump up^ van Gorp F, Whyte IM, Isbister GK (2009). “Clinical and ECG effects of escitalopram overdose”. Ann Emerg Med54 (3): 404–8. PMID 19556032doi:10.1016/j.annemergmed.2009.04.016.
  39. Jump up^ Haupt D (1996). “Determination of citalopram enantiomers in human plasma by liquid chromatographic separation on a Chiral-AGP column”. J. Chromatogr. B, Biomed. Appl685(2): 299–305. PMID 8953171doi:10.1016/s0378-4347(96)00177-6.
  40. Jump up^ Baselt RC (2008). Disposition of toxic drugs and chemicals in man (8th ed.). Foster City, Ca: Biomedical Publications. pp. 552–553. ISBN 0962652377.
  41. Jump up^ White N, Litovitz T, Clancy C (December 2008). “Suicidal antidepressant overdoses: a comparative analysis by antidepressant type”Journal of Medical Toxicology4 (4): 238–250. PMC 3550116Freely accessiblePMID 19031375doi:10.1007/BF03161207.
  42. Jump up^ Owens, MJ; Knight, DL; Nemeroff, CB (1 September 2001). “Second-generation SSRIs: human monoamine transporter binding profile of escitalopram and R-fluoxetine.”. Biological Psychiatry50 (5): 345–50. PMID 11543737doi:10.1016/s0006-3223(01)01145-3.
  43. Jump up to:a b Brunton L, Chabner B, Knollman B. Goodman and Gilman’s The Pharmacological Basis of Therapeutics, Twelfth Edition. McGraw Hill Professional; 2010.
  44. Jump up^ For an overview of supporting data, see Sánchez C, Bøgesø KP, Ebert B, Reines EH, Braestrup C (2004). “Escitalopram versus citalopram: the surprising role of the R-enantiomer”. Psychopharmacology174 (2): 163–76. PMID 15160261doi:10.1007/s00213-004-1865-z.
  45. Jump up^ Chen F, Larsen MB, Sánchez C, Wiborg O (2005). “The (S)-enantiomer of (R,S)-citalopram, increases inhibitor binding to the human serotonin transporter by an allosteric mechanism. Comparison with other serotonin transporter inhibitors”. European Neuropsychopharmacology15 (2): 193–198. PMID 15695064doi:10.1016/j.euroneuro.2004.08.008.
  46. Jump up^ Mansari ME, Wiborg O, Mnie-Filali O, Benturquia N, Sánchez C, Haddjeri N (2007). “Allosteric modulation of the effect of escitalopram, paroxetine and fluoxetine: in-vitro and in-vivo studies”. The International Journal of Neuropsychopharmacology10 (1): 31–40. PMID 16448580doi:10.1017/S1461145705006462.
  47. Jump up to:a b O’Brien FE, O’Connor RM, Clarke G, Dinan TG, Griffin BT, Cryan JF (October 2013). “P-glycoprotein inhibition increases the brain distribution and antidepressant-like activity of escitalopram in rodents”Neuropsychopharmacology38 (11): 2209–2219. PMC 3773671Freely accessiblePMID 23670590doi:10.1038/npp.2013.120.
  48. Jump up^ Ali Torkamani. “Selective Serotonin Reuptake Inhibitors and CYP2D6” Retrieved 14 May 2015.
  49. Jump up^ Noehr-Jensen, L; Zwisler, ST; Larsen, F; Sindrup, SH; Damkier, P; Brosen, K (December 2009). “Escitalopram is a weak inhibitor of the CYP2D6-catalyzed O-demethylation of (+)-tramadol but does not reduce the hypoalgesic effect in experimental pain.”. Clinical pharmacology and therapeutics86 (6): 626–33. PMID 19710642doi:10.1038/clpt.2009.154.
  50. Jump up^ “2000 Annual Report. p 28 and 33” (PDF). Lundbeck. 2000. Retrieved 2007-04-07.
  51. Jump up^ Miranda Hitti. “FDA OKs Generic Depression Drug – Generic Version of Lexapro Gets Green Light”. WebMD. Retrieved 2007-10-10.
  52. Jump up^ Marie-Eve Laforte (2006-07-14). “US court upholds Lexapro patent”. FirstWord. Retrieved 2007-10-10.
  53. Jump up^ “Forest Laboratories Receives Patent Term Extension for Lexapro” (Press release). PRNewswire-FirstCall. 2006-03-02. Retrieved 2009-01-19.
  54. Jump up^ “Forest Laboratories: A Tale of Two Whistleblowers” article by Alison Frankel in The American Lawyer February 27, 2009
  55. Jump up^ United States of America v. Forest Laboratories Full text of the federal complaint filed in the US District Court for the district of Massachusetts
  56. Jump up^ “Drug Maker Is Accused of Fraud” article by Barry Meier and Benedict Carey in The New York Times February 25, 2009
  57. Jump up^ “Forest Laboratories, Inc. Provides Statement in Response to Complaint Filed by U.S. Government” Forest press-release. February 26, 2009.
  58. Jump up^ “Drug Maker Forest Pleads Guilty; To Pay More Than $313 Million to Resolve Criminal Charges and False Claims Act Allegations”

Cited texts

Further reading

External links

Clinical data
Pronunciation About this sound pronunciation 
Trade names Cipralex, Lexapro and many others[1]
AHFS/ Monograph
MedlinePlus a603005
License data
  • AU: C
  • US: C (Risk not ruled out)
Routes of
ATC code
Legal status
Legal status
  • AU: S4 (Prescription only)
  • CA℞-only
  • UK: POM (Prescription only)
  • US: ℞-only
  • In general: ℞ (Prescription only)
Pharmacokinetic data
Bioavailability 80%
Protein binding ~56%
Metabolism Liver, specifically the enzymes CYP3A4 and CYP2C19
Biological half-life 27–32 hours
CAS Number
PubChem CID
Chemical and physical data
Formula C20H21FN2O
Molar mass 324.392 g/mol
(414.43 as oxalate)
3D model (JSmol)

///////////////////S-(+)-Citalopram, эсциталопрам إيسكيتالوبرام 艾司西酞普兰 , CITALOPRAM

Amantadine Hydrochloride, アダマンタン-1-アミン , تادين ,Амантадин , 金刚烷胺 , アマンタジン


ChemSpider 2D Image | Amantadine | C10H17N


  • Molecular Formula C10H17N
  • Average mass 151.249 Da
1-adamantanamine; 1-adamantylamine; 1-aminoadamantane; Amantidine; Aminoadamantane
1-Aminotricyclo( 3,7))decane
2204333 [Beilstein]
31377-23-8 [RN]
40933-03-7 [RN]
4-pyridinecarboxylic acid, compd. with tricyclo[,7]decan-1-amine (1:1)
Journal of the American Chemical Society, 91, p. 6457, 1969 DOI: 10.1021/ja01051a047
Synthesis, p. 457, 1976
Amantadine Hydrochloride - API


  • Molecular FormulaC10H18ClN
  • Average mass187.710 Da
CAS 665-66-7
13 C NMR
Image result for Amantadine NMR

Amantadine (trade name Symmetrel, by Endo Pharmaceuticals) is a drug that has U.S. Food and Drug Administration approval for use both as an antiviral and an antiparkinsonian drug. It is the organic compound 1-adamantylamine or 1-aminoadamantane, meaning it consists of an adamantane backbone that has an amino group substituted at one of the four methyne positions. Rimantadineis a closely related derivative of adamantane with similar biological properties.

Apart from medical uses, this compound is useful as a building block in organic synthesis, allowing the insertion of an adamantyl group.

According to the U.S. Centers for Disease Control and Prevention (CDC) 100% of seasonal H3N2 and 2009 pandemic flu samples tested showed resistance to adamantanes, and amantadine is no longer recommended for treatment of influenza in the United States. Additionally, its effectiveness as an antiparkinsonian drug is undetermined, with a 2003 Cochrane Review concluding that there was insufficient evidence in support of or against its efficacy and safety.[2]

Medical uses

Parkinson’s disease

Amantadine is used to treat Parkinsons disease, as well as parkinsonism syndromes.[3] A 2003 Cochrane review concluded evidence was inadequate to support the use of amantadine for Parkinson’s disease.[2]

An extended release formulation is used to treat dyskinesia, a side effect of levodopa which is taken by people who have Parkinsons.[4]


Amantadine is no longer recommended for treatment of influenza A infection. For the 2008/2009 flu season, the CDC found that 100% of seasonal H3N2 and 2009 pandemic flu samples tested have shown resistance to adamantanes.[5] The CDC issued an alert to doctors to prescribe the neuraminidase inhibitors oseltamivir and zanamivir instead of amantadine and rimantadine for treatment of flu.[6][7] A 2014 Cochrane review did not find benefit for the prevention or treatment of influenza A.[8]

Fatigue in multiple sclerosis

Amantadine also seems to have moderate effects on multiple sclerosis (MS) related fatigue.[9]

Adverse effects

Amantadine has been associated with several central nervous system (CNS) side effects, likely due to amantadine’s dopaminergic and adrenergic activity, and to a lesser extent, its activity as an anticholinergic. CNS side effects include nervousness, anxiety, agitation, insomnia, difficulty in concentrating, and exacerbations of pre-existing seizure disorders and psychiatric symptoms in patients with schizophrenia or Parkinson’s disease. The usefulness of amantadine as an anti-parkinsonian drug is somewhat limited by the need to screen patients for a history of seizures and psychiatric symptoms.

Rare cases of severe skin rashes, such as Stevens-Johnson syndrome,[10] and of suicidal ideation have also been reported in patients treated with amantadine.[11][12]

Livedo reticularis is a possible side effect of amantadine use for Parkinson’s disease.[13]


The mechanisms for amantadine’s antiviral and antiparkinsonian effects are unrelated. The mechanism of amantadine’s antiviral activity involves interference with the viral protein, M2, a proton channel.[14][15] After entry of the virus into cells via endocytosis, it is localized in acidic vacuoles; the M2 channel functions in transporting protons with the gradient from the vacuolar space into the interior of the virion. Acidification of the interior results in disassociation of ribonucleoproteins, and the initiation of viral replication. Amantadine and rimantadine function in a mechanistically identical fashion in entering the barrel of the tetrameric M2 channel, and blocking pore function (i.e., proton translocation). Resistance to the drug class is a consequence of mutations to the pore-lining residues of the channel, leading to the inability of the sterically bulky adamantane ring that both amantadine and rimantadine share, in entering in their usual way, into the channel.[citation needed]

Influenza B strains possess a structurally distinct M2 channels with channel-facing side chains that fully obstruct the channel vis-a-vis binding of adamantine-class channel inhibitors, while still allowing proton flow and channel function to occur; this constriction in the channels is responsible for the ineffectiveness of this drug and rimantadine towards all circulating Influenza B strains.

Parkinson’s disease

Amantadine is a weak antagonist of the NMDA-type glutamate receptorincreases dopamine release, and blocks dopamine reuptake.[16] Amantadine probably does not inhibit MAO enzyme.[17] Moreover, the mechanism of its antiparkinsonian effect is poorly understood.[citation needed] The drug has many effects in the brain, including release of dopamine and norepinephrine from nerve endings. It appears to be a weak NMDA receptor antagonist[18][19] as well as an anticholinergic, specifically a nicotinic alpha-7 antagonist like the similar pharmaceutical memantine.

In 2004, it was discovered that amantadine and memantine bind to and act as agonists of the σ1 receptor (Ki = 7.44 µM and 2.60 µM, respectively), and that activation of the σ1receptor is involved in the dopaminergic effects of amantadine at therapeutically relevant concentrations.[20] These findings may also extend to the other adamantanes such as adapromine, rimantadine, and bromantane, and could explain the psychostimulant-like effects of this family of compounds.[20]


Amantadine was approved by the U.S. Food and Drug Administration in October 1966 as a prophylactic agent against Asian influenza, and eventually received approval for the treatment of influenzavirus A[21][22][23][24] in adults. In 1969, the drug was also discovered by accident upon trying to help reduce symptoms of Parkinson’s disease, drug-induced extrapyramidal syndromes, and akathisia.

In 2017, the U.S. Food and Drug Administration approved the use of amantadine in an extended release formulation developed by Adamas Pharma for the treatment of dyskinesia, an adverse effect of levodopa, that people with Parkinson’s experience.[25]

Veterinary misuse

In 2005, Chinese poultry farmers were reported to have used amantadine to protect birds against avian influenza.[26] In Western countries and according to international livestock regulations, amantadine is approved only for use in humans. Chickens in China have received an estimated 2.6 billion doses of amantadine.[26] Avian flu (H5N1) strains in China and southeast Asia are now resistant to amantadine, although strains circulating elsewhere still seem to be sensitive. If amantadine-resistant strains of the virus spread, the drugs of choice in an avian flu outbreak will probably be restricted to the scarcer and costlier oseltamivir and zanamivir, which work by a different mechanism and are less likely to trigger resistance.

On September 23, 2015, the US Food and Drug Administration announced the recall of Dingo Chip Twists “Chicken in the Middle” dog treats because the product has the potential to be contaminated with amantadine.[27]

Image result for Amantadine SYNTHESIS

Image result for Amantadine SYNTHESIS

Image result for Amantadine SYNTHESIS


An Improved Synthesis of Amantadine Hydrochloride

 Vietnam Military Medical University, No. 160, Phung Hung str., Phuc La ward, Ha Dong district, Hanoi, Vietnam
 School of Chemical Engineering, Hanoi University of Science and Technology, No.1, Dai Co Viet str., Bach Khoa ward, Hai Ba Trung district, Hanoi, Vietnam
Org. Process Res. Dev., Article ASAP
DOI: 10.1021/acs.oprd.7b00242
Abstract Image

Amantadine hydrochloride 1 is an antiviral drug used in the prevention and treatment of influenza A infections. It has also been used for alleviating early symptoms of Parkinson’s disease. Several methods for the preparation of 1 have been reported. These procedures started with adamantane 2 using as many as four reaction steps to produce amantadine hydrochloride with overall yields ranging from 45% to 58%. In this article, we describe a two-step procedure for the synthesis of 1from 2 via N-(1-adamantyl)acetamide 4 with an improved overall yield of 67%. The procedure was also optimized to reduce the use of toxic solvents and reagents, rendering it more environment-friendly. The procedure can be considered as suitable for large-scale production of amantadine hydrochloride. The structure of amantadine hydrochloride was confirmed by 1H NMR, 13C NMR, IR, and MS.

Amantadine Hydrochloride (1)

 1. Yield: 232 g (82%). Rf = 0.5 (CHCl3/MeOH/25% aqueous NH3 = 6:1:1).
Purity (GC): 99.22%, tR 10.10 min; mp 360 °C.
1H NMR (CDCl3, 500 MHz): δ 8.28 (br, s, 3H), 2.15 (s, 3H), 2.04 (s, 6H); 1.69 (s, 6H).
13C NMR (CDCl3, 125 MHz): δ 52.95, 40.56, 35.38, 28.97.
IR (KBr): cm–1 3331.73–3185.17 (N–H); 3054.60–2917.82 (C–H); 1363.50 (C–N).
MS: m/z = 151.9 [M + 1]+, 135.0 [M–NH2 – 1]+.
IR spectrum of amantadine hydrochloride (1)
MS spectrum of amantadine hydrochloride
1H-NMR spectrum of amantadine hydrochloride (1) in CDCl3
13C-NMR spectrum of amantadine hydrochloride (1) in CDCl3
Title: Amantadine
CAS Registry Number: 768-94-5
CAS Name: Tricyclo[,7]decan-1-amine
Additional Names: 1-adamantanamine; 1-aminoadamantane; 1-aminodiamantane (obsolete); 1-aminotricyclo[,7]decane
Molecular Formula: C10H17N
Molecular Weight: 151.25
Percent Composition: C 79.41%, H 11.33%, N 9.26%
Literature References: NMDA-receptor antagonist; also active vs influenza A virus. Prepn: H. Stetter et al., Ber. 93, 226 (1960); W. Haaf, ibid. 97, 3234 (1964); P. Kovacic, P. D. Roskos, Tetrahedron Lett. 1968, 5833. Antiviral activity: W. L. Davies et al.,Science 144, 862 (1964). GC determn in biological samples and pharmacodynamics: W. E. Bleidner et al., J. Pharmacol. Exp. Ther. 150, 484 (1965). Pharmacology and toxicology: V. G. Vernier et al., Toxicol. Appl. Pharmacol. 15, 642 (1969). Comprehensive description: J. Kirschbaum, Anal. Profiles Drug Subs. 12, 1-36 (1983). Review of use vs influenza A: R. L. Tominack, F. G. Hayden, Infect. Dis. Clin. North Am. 1, 459-478 (1987); of pharmacokinetics: F. Y. Aoki, D. S. Sitar, Clin. Pharmacokinet. 14, 35-51 (1988). Review of NMDA receptor binding and neuroprotective properties: J. Kornhuber et al., J. Neural Transm. 43, Suppl., 91-104 (1994). Series of articles on clinical experience in Parkinson’s disease: ibid. 46, Suppl., 399-421 (1995).
Properties: Crystals by sublimation, mp 160-190° (closed tube) (Stetter). Also reported as mp 180-192° (Haaf). pKa: 10.1. Sparingly sol in water.
Melting point: mp 160-190° (closed tube) (Stetter); mp 180-192° (Haaf)
pKa: pKa: 10.1

Derivative Type: Hydrochloride

CAS Registry Number: 665-66-7
Manufacturers’ Codes: EXP-105-1; NSC-83653
Trademarks: Adekin (Desitin); Lysovir (Alliance); Mantadan (Boehringer, Ing.); Mantadine (Endo); Mantadix (BMS); Symmetrel (Endo); Virofral (Novo)
Molecular Formula: C10H17N.HCl
Molecular Weight: 187.71
Percent Composition: C 63.99%, H 9.67%, N 7.46%, Cl 18.89%
Properties: Crystals from abs ethanol + anhydr ether, mp >360° (dec). Freely sol in water (at least 1:20); sol in alcohol, chloroform. Practically insol in ether. LD50 orally in mice, rats: 700, 1275 mg/kg (Vernier).
Melting point: mp >360° (dec)
Toxicity data: LD50 orally in mice, rats: 700, 1275 mg/kg (Vernier)
Derivative Type: Sulfate
CAS Registry Number: 31377-23-8
Trademarks: PK-Merz (Merz)
Molecular Formula: C10H17N.½H2SO4
Molecular Weight: 200.29
Percent Composition: C 59.97%, H 9.06%, N 6.99%, S 8.00%, O 15.98%
Therap-Cat: Antiviral; antiparkinsonian.
Keywords: Antidyskinetic; Antiparkinsonian; Antiviral.
Amantadine ball-and-stick model.png
Clinical data
Trade names Symmetrel
Synonyms 1-Adamantylamine
AHFS/ Monograph
MedlinePlus a682064
  • AU: B3
  • US: C (Risk not ruled out)
Routes of
ATC code
Legal status
Legal status
Pharmacokinetic data
Bioavailability 86–90%[1]
Protein binding 67%[1]
Metabolism Minimal (mostly to acetyl metabolites)[1]
Biological half-life 10–31 hours[1]
Excretion Urine[1]
CAS Number
PubChem CID
ECHA InfoCard 100.011.092
Chemical and physical data
Formula C10H17N
Molar mass 151.249 g/mol
3D model (JSmol)


  1. Jump up to:a b c d e “SYMMETREL® (amantadine hydrochloride)” (PDF). TGA eBusiness Services. NOVARTIS Pharmaceuticals Australia Pty Limited. 29 June 2011. Retrieved 24 February2014.
  2. Jump up to:a b Crosby, Niall J; Deane, Katherine; Clarke, Carl E (2003). Clarke, Carl E, ed. “Amantadine in Parkinson’s disease”. Cochrane Database of Systematic Reviewsdoi:10.1002/14651858.CD003468.
  3. Jump up^ “Amantadine – FDA prescribing information,” Retrieved 2017-08-28.
  4. Jump up^ “Amantadine extended release capsules” (PDF). FDA. August 2017. For label updates, see FDA index page for NDA 208944
  5. Jump up^ CDC weekly influenza report – week 35,
  6. Jump up^ “CDC Recommends against the Use of Amantadine and Rimantadine for the Treatment or Prophylaxis of Influenza in the United States during the 2005–06 Influenza Season”CDC Health AlertCenters for Disease Control and Prevention. 2006-01-14. Archived from the original on 3 May 2008. Retrieved 2008-05-20.
  7. Jump up^ Deyde, Varough M.; Xu, Xiyan; Bright, Rick A.; Shaw, Michael; Smith, Catherine B.; Zhang, Ye; Shu, Yuelong; Gubareva, Larisa V.; Cox, Nancy J.; Klimov, Alexander I. (2007). “Surveillance of Resistance to Adamantanes among Influenza A(H3N2) and A(H1N1) Viruses Isolated Worldwide”. Journal of Infectious Diseases196 (2): 249–257. PMID 17570112doi:10.1086/518936.
  8. Jump up^ Alves Galvão, MG; Rocha Crispino Santos, MA; Alves da Cunha, AJ (21 November 2014). “Amantadine and rimantadine for influenza A in children and the elderly.”. The Cochrane database of systematic reviews11: CD002745. PMID 25415374doi:10.1002/14651858.CD002745.pub4.
  9. Jump up^ Braley, TJ; Chervin, RD (Aug 2010). “Fatigue in multiple sclerosis: mechanisms, evaluation, and treatment.”Sleep33 (8): 1061–7. PMC 2910465Freely accessiblePMID 20815187.
  10. Jump up^ Singhal, KC; Rahman, SZ (2002). “Stevens Johnson Syndrome Induced by Amantadine”. Rational Drug Bulletin12 (1): 6.
  11. Jump up^ “Symmetrel (Amantadine) Prescribing Information” (PDF). Endo Pharmaceuticals. May 2003. Retrieved 2007-08-02.
  12. Jump up^ Cook, PE; Dermer, SW; McGurk, T (1986). “Fatal overdose with amantadine”. Canadian Journal of Psychiatry31 (8): 757–8. PMID 3791133.
  13. Jump up^ Vollum, DI; Parkes, JD; Doyle, D (June 1971). “Livedo reticularis during amantadine treatment”Br Med J2 (5762): 627–8. PMC 1796527Freely accessiblePMID 5580722doi:10.1136/bmj.2.5762.627.
  14. Jump up^ Wang C, Takeuchi K, Pinto LH, Lamb RA (1993). “Ion channel activity of influenza A virus M2 protein: characterization of the amantadine block”Journal of Virology67 (9): 5585–94. PMC 237962Freely accessiblePMID 7688826.
  15. Jump up^ Jing X, Ma C, Ohigashi Y, et al. (2008). “Functional studies indicate amantadine binds to the pore of the influenza A virus M2 proton-selective ion channel”Proc. Natl. Acad. Sci. U.S.A105 (31): 10967–72. PMC 2492755Freely accessiblePMID 18669647doi:10.1073/pnas.0804958105.
  16. Jump up^ Jasek, W, ed. (2007). Austria-Codex (in German) (62nd ed.). Vienna: Österreichischer Apothekerverlag. p. 3962. ISBN 978-3-85200-181-4.
  17. Jump up^ Strömberg, U.; Svensson, T. H. (November 1971). “Further Studies on the Mode of Action of Amantadine”wiley.comActa Pharmacologica et Toxicologica, Nordic Pharmacological Society. 30 (3–4): 161–171. doi:10.1111/j.1600-0773.1971.tb00646.x.
  18. Jump up^ Kornhuber, J; Bormann, J; Hübers, M; Rusche, K; Riederer, P (1991). “Effects of the 1-amino-adamantanes at the MK-801-binding site of the NMDA-receptor-gated ion channel: a human postmortem brain study”. Eur. J. Pharmacol. Mol. Pharmacol. Sect206: 297–300. doi:10.1016/0922-4106(91)90113-v.
  19. Jump up^ Blanpied, TA; Clarke, RJ; Johnson, JW (2005). “Amantadine inhibits NMDA receptors by accelerating channel closure during channel block”. Journal of Neuroscience25 (13): 3312–22. PMID 15800186doi:10.1523/JNEUROSCI.4262-04.2005.
  20. Jump up to:a b Peeters, Magali; Romieu, Pascal; Maurice, Tangui; Su, Tsung-Ping; Maloteaux, Jean-Marie; Hermans, Emmanuel (2004). “Involvement of the sigma1 receptor in the modulation of dopaminergic transmission by amantadine”. European Journal of Neuroscience19 (8): 2212–2220. ISSN 0953-816XPMID 15090047doi:10.1111/j.0953-816X.2004.03297.x.
  21. Jump up^ Hounshell, David A.; Kenly Smith, John (1988). Science and Corporate Strategy: Du Pont R&D, 1902–1980. Cambridge University Press. p. 469.
  22. Jump up^ “Sales of flu drug by du Pont unit a ‘disappointment'”The New York Times. Wilmington, Delaware. October 5, 1982. Retrieved May 19, 2008.
  23. Jump up^ Maugh, T. (1979). “Panel urges wide use of antiviral drug”. Science206 (4422): 1058–60. PMID 386515doi:10.1126/science.386515.
  24. Jump up^ Maugh, T. H. (1976). “Amantadine: an Alternative for Prevention of Influenza”. Science192 (4235): 130–1. PMID 17792438doi:10.1126/science.192.4235.130.
  25. Jump up^ Bastings, Eric. “NDA 208944 Approval Letter” (PDF).
  26. Jump up to:a b Sipress, Alan (2005-06-18). “Bird Flu Drug Rendered Useless”Washington Post. pp. A01. Retrieved 2007-08-02.
  27. Jump up^ “Enforcement Report – Week of September 23, 2015” US Food and Drug Administration, US Department of Health & Human Services.


 JTV 519, K 201, 



  • Molecular FormulaC25H32N2O2S
  • Average mass424.599 Da
  • 145903-06-6 CAS

ChemSpider 2D Image | JTV-519 hydrochloride salt | C25H33ClN2O2S

JTV-519 hydrochloride salt

  • Molecular FormulaC25H33ClN2O2S
  • Average mass461.060 Da
3-(4-Benzyl-1-piperidinyl)-1-(7-methoxy-2,3-dihydro-1,4-benzothiazepin-4(5H)-yl)-1-propanonhydrochlorid (1:1)
4-[3-(4-benzylpiperidin-1-yl)propanoyl]-7-methoxy-2,3,4,5-tetrahydro-1,4-benzothiazepine hydrochloride
JTV-519 hydrochloride salt
1038410-88-6 [RN]
  1. UNII-0I621Y6R4Q
  2. K201
  3. 1038410-88-6
  4. K 201
  5. SCHEMBL194018
  6. CHEMBL2440857
  7. DTXSID90146108
  8. 0I621Y6R4Q
  9. LS-193564

Image result for Andrew Marks, JAPAN TOBACCO


Acute Myocardial Infarction, Treatment of Cardiovascular Diseases (Not Specified)
Antiarrhythmic Drugs

JTV-519 (K201) is a 1,4-benzothiazepine derivative that interacts with many cellular targets.[1] It has many structural similarities to diltiazem, a Ca2+ channel blocker used for treatment of hypertensionangina pectoris and some types of arrhythmias.[2] JTV-519 acts in the sarcoplasmic reticulum (SR) of cardiac myocytes by binding to and stabilizing the ryanodine receptor (RyR2) in its closed state.[3][4]It can be used in the treatment of cardiac arrhythmias, heart failurecatecholaminergic polymorphic ventricular tachycardia (CPVT) and store overload-induced Ca2+ release (SOICR).[2][3][4] Currently, this drug has only been tested on animals and its side effects are still unknown.[5] As research continues, some studies have also found a dose-dependent response; where there is no improvement seen in failing hearts at 0.3 μM and a decline in response at 1 μM.[4]

K-201 (JTV-519; 1,4-benzothiazepine derivative) is an antiarrhythmic drug, had been in phase II clinical development at Japan Tobacco and Sequel Pharmaceuticals for the intravenous treatment of atrial fibrillation; however no recent developments have been reported and Sequel Pharmaceuticals has ceased operations.

In 2006, NovaCardia acquired rights from Aetas to develop the product in Europe and US for cardiovascular disorders. Sequel acquired the compound, which has a unique multi-ion channel profile, from NovaCardia following its acquisition by Merck & Co.

Treatment with JTV-519 involves stabilization of RyR2 in its closed state, decreasing its open probability during diastole and inhibiting a Ca2+ leak into the cell’s cytosol.[3][4] By decreasing the intracellular Ca2+ leak, it is able to prevent Ca2+ sparks or increases in the resting membrane potential, which can lead to spontaneous depolarization (cardiac arrhythmias), and eventually heart failure, due to the unsynchronized contraction of the atrial and ventricular compartments of the heart.[2][3][4] When Ca2+ sparks occur from the SR, the increase in intracellular Ca2+ contributes to the rising membrane potential which leads to the irregular heart beat associated to cardiac arrhythmias.[3] It can also prevent SOICR in the same manner; preventing opening of the channel due to the increase of Ca2+ inside the SR levels beyond its threshold.[2]

Molecular problem

In the closed state, N-terminal and central domains come into close contact interacting to cause a “zipping” of domains. This leads to conformational constraints that stabilize the channel and maintain the closed state.[1] Most RyR2 mutations are clustered into three regions of the channel, all affecting the same domains that interact to stabilize the channel.[1] Any of these mutations can lead to “unzipping” of the domains and a decrease in the energy barrier required for opening the channel (increasing its open probability).[1]This channel “unzipping” allows for an increase in protein kinase A phosphorylation and calstabin2 dissociation. Phosphorylation of RyR2 increases the channel’s response to Ca2+, which usually binds the RyR2 to open it.[1] If the channel become phosphorylated, this can lead to an increase in Ca2+ sparks due to an increase in Ca2+ sensitivity.

Some researchers believe that the depletion of calstabin2 from the RyR2 causes the calcium leak.[3] The depletion of calstabin2 can occur in both heart failure and CPVT.[3]Calstabin2 is a protein that stabilizes RyR2 in its closed state, preventing Ca2+ leakage during diastole. When calstabin2 is lost, the interdomain interactions of RyR2 become loose, allowing the Ca2+ leak.[3] However, the role of calstabin2 has been controversial, as some studies have found it necessary for the effect of JTV-519,[3] whereas others have found the drug functions without the stabilizing protein.[2]

Molecular mechanism

JTV-519 seems to restore the stable conformation of RyR2 during the closed state.[1][4] It is still controversial whether or not calstabin2 is necessary for this process, however, many studies believe that JTV-519 can act directly on the channel and by binding, prevents conformational changes.[2] This stabilization of the channel decreases its open probability resulting in fewer leaks of Ca2+ into the cytosol and fewer Ca2+ sparks to occur.[3][4] Researchers who believe that calstabin2 is necessary for JTV-519 effect, found that this drug may function by inducing the binding of calstabin2 back to the channel or increasing calstabin2’s affinity for the RyR2 and thus increasing its stability.[2][3]



US 20050186640

Inventors Andrew MarksDonald LandryShi DengZhen Cheng
Original Assignee Marks Andrew R.Landry Donald W.Deng Shi X.Cheng Zhen Z.


WO 9212148

Inventors Noboru KanekoTatsushi OosawaTeruyuki SakaiHideo Oota
Applicant Noboru Kaneko


US 2014121368

2,3,4,5-tetrahydrobenzo[f][1,4]thiazepines are important compounds because of their biological activities, as disclosed, for example, in U.S. Pat. Nos. 5,416,066 and 5,580,866 and published US Patent Applications Nos. 2005/0215540, 2007/0049572 and 2007/0173482.

Synthetic procedures exist for the preparation of 2-oxo-, 3-oxo-, 5-oxo- and 3,5-dioxo-1,4-benzothiazepines and for 2,3-dihydro-1,4-benzothiazepines. However, relatively few publications describe the preparation of 2,3,4,5-tetrahydrobenzo-1,4-thiazepines that contain no carbonyl groups, and most of these involve reduction of a carbonyl group or an imine. Many of the routes described in the literature proceed from an ortho-substituted arene and use the ortho substituents as “anchors” for the attachment of the seven-membered ring. Essentially all the preparatively useful syntheses in the literature that do not begin with an ortho-substituted arene employ a modification of the Bischler-Napieralski reaction in which the carbon of the acyl group on the γ-amide becomes the carbon adjacent the bridgehead and the acyl substituent becomes the 5-substituent. Like earlier mentioned syntheses, the Bischler-Napieralski synthesis requires reduction of an iminium intermediate.

It would be useful to have an intramolecular reaction for the direct construction of 2,3,4,5-tetrahydrobenzo[1,4]thiazepines that would allow more flexibility in the 4- and 5-substituents and that would avoid a separate reduction step. The Pictet Spengler reaction, in which a β-arylethylamine such as tryptamine undergoes 6-membered ring closure after condensation (cyclization) with an aldehyde, has been widely used in the synthesis of 6-membered ring systems over the past century and might be contemplated for this purpose. The Pictet Spengler reaction, however, has not been generally useful for 7-membered ring systems such as 1,4-benzothiazepines. A plausible explanation is that the failure of the reaction for typical arenes was due to the unfavorable conformation of the 7-membered ring. There are two isolated examples of an intramolecular Pictet-Spengler-type reaction producing a good yield of a benzothiazepine from the addition of formaldehyde. In one case, the starting material was a highly unusual activated arene (a catechol derivative) [Manini et al. J. Org. Chem. (2000), 65, 4269-4273]. In the other case, the starting material is a bis(benzotriazolylmethyl)amine that cyclizes to a mono(benzotriazolyl)benzothiazole [Katritzky et al. J. Chem. Soc. Pl (2002), 592-598].


US 20050186640

WO 2015031914

US 20040229781

US 20090292119

US 7704990


Journal of Medicinal Chemistry (2013), 56(21), 8626-8655


Synthesis of 2,3,4,5-Tetrahydrobenzo[1,4]thiazepines via N-Acyliminium Cyclization

 ARMGO Pharma, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591, United States
 Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York 10032, United States
Org. Process Res. Dev., Article ASAP
DOI: 10.1021/acs.oprd.7b00260
Publication Date (Web): September 28, 2017
Copyright © 2017 American Chemical Society
*Phone: (914)-425-0000. E-mail:


Abstract Image

We report an efficient and scalable synthesis of 7-methoxy-2,3,4,5-tetrahydrobenzo[1,4]thiazepine, the core structure of biologically active molecules like JTV-519 and S107. This synthetic route, starting with 4-methoxythiophenol and proceeding via acyliminum cyclization, gives the target product in four steps and 68% overall yield and is a substantial improvement over previously published processes. Nine additional examples of tetrahydrobenzo[1,4]thiazepine synthesis via acyliminium ring closure are also presented.


  1. Jump up to:a b c d e f Oda, T; Yano, M; Yamamoto, T; Tokuhisa, T; Okuda, S; Doi, M; Ohkusa, T; Ikeda, Y; et al. (2005). “Defective regulation of interdomain interactions within the ryanodine receptor plays a key role in the pathogenesis of heart failure”. Circulation111 (25): 3400–10. PMID 15967847doi:10.1161/CIRCULATIONAHA.104.507921.
  2. Jump up to:a b c d e f g Hunt, DJ; Jones, PP; Wang, R; Chen, W; Bolstad, J; Chen, K; Shimoni, Y; Chen, SR (2007). “K201 (JTV519) suppresses spontaneous Ca2+ release and 3Hryanodine binding to RyR2 irrespective of FKBP12.6 association”The Biochemical Journal404 (3): 431–8. PMC 1896290Freely accessiblePMID 17313373doi:10.1042/BJ20070135.
  3. Jump up to:a b c d e f g h i j k Wehrens, XH; Lehnart, SE; Reiken, SR; Deng, SX; Vest, JA; Cervantes, D; Coromilas, J; Landry, DW; Marks, AR (2004). “Protection from cardiac arrhythmia through ryanodine receptor-stabilizing protein calstabin2”. Science304 (5668): 292–6. PMID 15073377doi:10.1126/science.1094301.
  4. Jump up to:a b c d e f g Toischer, K; Lehnart, SE; Tenderich, G; Milting, H; Körfer, R; Schmitto, JD; Schöndube, FA; Kaneko, N; et al. (2010). “K201 improves aspects of the contractile performance of human failing myocardium via reduction in Ca2+ leak from the sarcoplasmic reticulum”Basic research in cardiology105 (2): 279–87. PMC 2807967Freely accessiblePMID 19718543doi:10.1007/s00395-009-0057-8.
  5. Jump up^ Viswanathan, MN; Page, RL (2009). “Pharmacological therapy for atrial fibrillation: Current options and new agents”. Expert Opinion on Investigational Drugs18 (4): 417–31. PMID 19278302doi:10.1517/13543780902773410.
IUPAC name

Other names

3D model (JSmol)
PubChem CID
Molar mass 424.60 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

//////////////JTV-519K201, JTV 519, K 201, 

Phytomenadione, Phytonadione, фитоменадион ,فيتوميناديون ,

Vitamin K1.png

ChemSpider 2D Image | Phylloquinone | C31H46O2


PHYTONADIONE, Phylloquinone

Molecular Formula: C31H46O2
Molecular Weight: 450.707 g/mol
1,4-Naphthalenedione, 2-methyl-3-((2E,7R,11R)-3,7,11,15-tetramethyl-2-hexadecenyl)-
2′,3′-trans-Vitamin K1
фитоменадион [Russian] [INN]
فيتوميناديون [Arabic] [INN]
 CAS 84-80-0[RN]
Antihemorrhagic vitamin
Aqua mephyton
Combinal K1
Kativ N
Phylloquinone (8CI)
Optical Rotatory Power -0.28 ° Solv: 1,4-dioxane (123-91-1); Wavlen: 589.3 nm; Temp: 25 °CKarrer, P.; Helvetica Chimica Acta 1944, VOL 27, PG317-19








  1. Murahashi, Shun-ichi; European Journal of Organic Chemistry 2011, VOL2011(27), P5355-5365 
  2. Huang, Zhihong; Advanced Synthesis & Catalysis 2007, VOL349(4+5), PG539-545 



Phylloquinone is a family of phylloquinones that contains a ring of 2-methyl-1,4-naphthoquinone and an isoprenoid side chain. Members of this group of vitamin K 1 have only one double bond on the proximal isoprene unit. Rich sources of vitamin K 1 include green plants, algae, and photosynthetic bacteria. Vitamin K1 has antihemorrhagic and prothrombogenic activity.

Phytomenadione, also known as vitamin K1 or phylloquinone, is a vitamin found in food and used as a dietary supplement.[1][2] As a supplement it is used to treat certain bleeding disorders.[2] This includes in warfarin overdosevitamin K deficiency, and obstructive jaundice.[2] It is also recommended to prevent and treat hemorrhagic disease of the newborn.[2] Use is typically recommended by mouth or injection under the skin.[2] Use by injection into a vein or muscle is recommended only when other routes are not possible.[2] When given by injection benefits are seen within two hours.[2]

Common side effects when given by injection include pain at the site of injection and altered taste.[2] Severe allergic reactions may occur with injected into a vein or muscle.[2] It is unclear if use during pregnancy is safe; however, use is likely okay during breastfeeding.[3] It works by supplying a required component for making a number of blood clotting factors.[2] Found sources include green vegetables, vegetable oil, and some fruit.[4]

Phytomenadione was first isolated in 1939.[5] It is on the World Health Organization’s List of Essential Medicines, the most effective and safe medicines needed in a health system.[6] The wholesale cost in the developing world is about 0.11 to 1.27 USD for a 10 mg vial.[7]In the United States a course of treatment costs less than 25 USD.[8] In 1943 Edward Doisy and Henrik Dam were given a Nobel Prizefor its discovery.[5]


Phytomenadione is often called phylloquinone or vitamin K,[9] phytomenadione or phytonadione. Sometimes a distinction is made between phylloquinone, which is considered to be a natural substance, and phytonadione, which is considered to be a synthetic substance.[10]

stereoisomer of phylloquinone is called vitamin k1 (note the difference in capitalization).


Vitamin K is a fat-soluble vitamin that is stable in air and moisture but decomposes in sunlight. It is a polycyclic aromatic ketone, based on 2-methyl1,4-naphthoquinone, with a 3-phytyl substituent. It is found naturally in a wide variety of green plants, particularly in leaves, since it functions as an electron acceptor during photosynthesis, forming part of the electron transport chain of photosystem I.

Phylloquinone is an electron acceptor during photosynthesis, forming part of the electron transport chain of Photosystem I.

The best-known function of vitamin K in animals is as a cofactor in the formation of coagulation factors II (prothrombin), VII, IX, and X by the liver. It is also required for the formation of anticoagulant factors protein C and S. It is commonly used to treat warfarin toxicity, and as an antidote for coumatetralyl.

Vitamin K is required for bone protein formation.


e-EROS Encyclopedia of Reagents for Organic Synthesis, 1-2; 2001




Helvetica Chimica Acta (1944), 27, 317-19.


US 2683176

CN 105399615

WO 2016060670


  1. Jump up^ Watson, Ronald Ross (2014). Diet and Exercise in Cystic Fibrosis. Academic Press. p. 187. ISBN 9780128005880.
  2. Jump up to:a b c d e f g h i j “Phytonadione”. The American Society of Health-System Pharmacists. Retrieved 8 December 2016.
  3. Jump up^ “Phytonadione Use During Pregnancy” Retrieved 29 December 2016.
  4. Jump up^ “Office of Dietary Supplements – Vitamin K” 11 February 2016. Retrieved 30 December 2016.
  5. Jump up to:a b Sneader, Walter (2005). Drug Discovery: A History. John Wiley & Sons. p. 243. ISBN 9780471899792.
  6. Jump up^ “WHO Model List of Essential Medicines (19th List)” (PDF). World Health Organization. April 2015. Retrieved 8 December 2016.
  7. Jump up^ “Vitamin K1”International Drug Price Indicator Guide. Retrieved 8 December 2016.
  8. Jump up^ Hamilton, Richart (2015). Tarascon Pocket Pharmacopoeia 2015 Deluxe Lab-Coat Edition. Jones & Bartlett Learning. p. 229. ISBN 9781284057560.
  9. Jump up^ Haroon, Y.; Shearer, M. J.; Rahim, S.; Gunn, W. G.; McEnery, G.; Barkhan, P. (June 1982). “The content of phylloquinone (vitamin K1) in human milk, cows’ milk, and infant formula foods determined by high-performance liquid chromatography”J. Nutr112 (6): 1105–1117. PMID 7086539.
  10. Jump up^ “Vitamin K”. Retrieved 2009-03-18.
Vitamin K1.png
Clinical data
Trade names Mephyton, others
Synonyms Vitamin K1, phytonadione, phylloquinone
AHFS/ Monograph
  • US: C (Risk not ruled out)
Routes of
by mouth, subQ, IM, IV
ATC code
CAS Number
PubChem CID
ECHA InfoCard 100.001.422
Chemical and physical data
Formula C31H46O2
Molar mass 450.70 g/mol
3D model (JSmol)

/////////////PHYTONADIONE, фитоменадион ,فيتوميناديون PHYTONADIONE, Phylloquinone

MELTING POINT : Yellow viscous oil (Ref. 0001)

REFRACTIVE INDEX : n20D=1.5263(Ref. 0010)

OPTICAL ROTATION : [a]25D=-28deg(Ref. 0001)Optical rotation
[Table ] (Ref. 0010)

SOLUBILITY : Insol in water. Sparingly sol in methanol; sol in ethanol, acetone, benzene, petr ether, hexane, dioxane, chloroform, ether, other fat solvents and in vegetable oils(Ref. 0001)
UV SPECTRA : Uv max (petr ether) 242, 248, 260, 269, 325 nm (E1%1cm396, 419, 383, 387, 68) (Ref. 0001). Uv max (ethanol) 243, 248, 262, 270, 330 nm (Ref. 0002).
(UV Ref. 0010)Em at 248 nm (EtOH) =18,900 (Ref. 0002/0006).

IR SPECTRA : (liquid) : 6.05m (CO), 6.21, 6.28m (aromatic nucleus) (Ref. 0008)
(IR Ref. 0010)
[Table 0002] (Ref. 0010)

NMR SPECTRA : at 60 MHz in CDCl3, i nternal standard Si(CH3)4: multiplet at 453-486 Hz (4 aromatic H), triplet at 302 Hz (J=7 Hz) (olefinic H at C2. , doublet at 201 Hz ) (J=7 Hz) (CH2.-1), singlet at 130 Hz (CH3-2), signal at 107 Hz (trans-methyl group at C3. .(Ref. 0008)
( NMR Ref. 0010) Proton magnetic resonance data

MASS SPECTRA : [Spectrum  (Ref. 0005)


AUTHOR : Anonym. (1989) Vitamin K1 in The Merck Index , 11th edition (Budavari, S., O’Neil, M. J., Smith, A., and Heckelman, P.E., eds), pp1580, Merck & Co., Inc., Rahway, N. J.
VOL : PAGE : – ()


AUTHOR : Dunphy,P.J., and Brodie,A.F.
TITLE : The structure and function of quinones in respiratory metabolism.
JOURNAL : Methods in Enzymology
VOL : 18 PAGE : 407 -461 (1971)


AUTHOR : Di Mari, S. J., Supple, J. H., and Rapoport, H.
TITLE : Mass spectra of naphthoquinones. Vitamin K1(20) PubMed ID:5910960
JOURNAL : J Am Chem Soc.
VOL : 88 PAGE : 1226-1232 (1966)


AUTHOR : Suttie,W.J. (1991) Vitamin K, in Handbook of Vitamins (2nd ed., Machlin,L.J., ed) , pp145-194, Marcel Dekker, Inc., New York
VOL : PAGE : – ()


AUTHOR : Kodaka,K., Ujiie,T.,Ueno,T., and Saito,M.
TITLE : Contents of Vitamin K1 and Chlorophyll in Green Vegetables.
JOURNAL : J Jpn Soc Nutr Food Sci
VOL : 39 PAGE : 124 -126 (1986)


AUTHOR : Mayer,H., and Isler,O .
TITLE : Synthesis of Vitamin K.
JOURNAL : Methods in Enzymology
VOL : 18 PAGE : 491 -547 (1971)


AUTHOR : Naruta,Y., and Maruyama,K.
TITLE : Regio- and sterocontrolled polyprenylation of quinones. A new synthetic method of vitamin K series.
JOURNAL : Chemistry Lett
VOL : PAGE : 881 -884 (1979)


AUTHOR : Sommer,P., and Kofler,M.
TITLE : Physicochemical Properties and Methods of Analysis of Phylloquinones, Menaquinones, Ubiquinones, and Related Compounds. PubMed ID:5340867
JOURNAL : Vitamins and Hormones
VOL : 24 PAGE : 349 -399 (1966)


AUTHOR : Bristol, J. A., Ratcliffe, J. V., Roth, D. A., Jacobs, M. A., Furie, B. C., and Furie, B.
TITLE : Biosynthesis of prothrombin: intracellular localization of the vitamin K-dependent carboxylase and the sites of gamma-carboxylation PubMed ID:8839851
JOURNAL : Blood.
VOL : 88 PAGE : 2585-2593 (1996)


AUTHOR : Usui, Y., Nishimura, N., Kobayashi, N., Okanoue, T., Kimoto, M., and Ozawa, K.
TITLE : Measurement of vitamin K in human liver by gradient elution high-performance liquid chromatography using platinum-black catalyst reduction and fluorimetric detection PubMed ID:2753953
JOURNAL : J Chromatogr.
VOL : 489 PAGE : 291-301 (1989)



A highly efficient Suzuki-Miyaura methylation of pyridines leading to the drug pirfenidone and its CD3 version (SD-560)

A highly efficient Suzuki-Miyaura methylation of pyridines leading to the drug pirfenidone and its CD3 version (SD-560)

Green Chem., 2017, Advance Article
DOI: 10.1039/C7GC01740E, Communication
Eliezer Falb, Konstantin Ulanenko, Andrey Tor, Ronen Gottesfeld, Michal Weitman, Michal Afri, Hugo Gottlieb, Alfred Hassner
The first methylation/deuteromethylation in green and nearly quantitative Suzuki-Miyaura routes to pirfenidone and its d3 analog SD-560, at 99% isotopic purity.

A highly efficient Suzuki–Miyaura methylation of pyridines leading to the drug pirfenidone and its CD3version (SD-560)

 Author affiliations


Efficient introduction of methyl or methyl-d3 into aromatic and heteroaromatic systems still presents a synthetic challenge. In particular, we were in search of a non-cryogenic synthesis of the 5-CD3 version of pirfenidone (4d, also known as Pirespa®, Esbriet® or Pirfenex®), one of the two drugs approved to date for retarding idiopathic pulmonary fibrosis (IPF), a serious, rare and fatal lung disease, with a life expectancy of 3–5 years. The methyl-deuterated version of pirfenidone (4e, also known as SD-560) was designed with the objective of attenuating the rate of drug metabolism, and our goal was to find a green methylation route to avoid the environmental and economic impact of employing alkyllithium at cryogenic temperatures. The examination of several cross-coupling strategies for the introduction of methyl or methyl-d3 into methoxypyridine and pyridone systems culminated in two green and nearly quantitative Suzuki–Miyaura cross-coupling routes in the presence of RuPhos ligand: the first, using commercially available methyl boronic acid or its CD3 analog and the second, employing potassium methyl trifluoroborate or CD3BF3K, the latter obtained by a new route in 88% yield. This led, on a scale of tens of grams, to the synthesis of pirfenidone (4d) and its d3 analog, SD-560 (4e), at 99% isotopic purity.

//////////pirfenidone, CD3 version, SD-560,

%d bloggers like this: