All about Drugs, live, by DR ANTHONY MELVIN CRASTO, Worldpeaceambassador, Worlddrugtracker, OPEN SUPERSTAR Helping millions, 100 million hits on google, pushing boundaries,2.5 lakh plus connections worldwide, 40 lakh plus VIEWS on this blog in 227 countries, 7 CONTINENTS ……A 90 % paralysed man in action for you, I am suffering from transverse mylitis and bound to a wheel chair, With death on the horizon, I have lot to acheive
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 AFRICURE PHARMA, ROW2TECH, NIPER-G, Department of Pharmaceuticals, Ministry of Chemicals and Fertilizers, Govt. of India as ADVISOR, earlier assignment was
with GLENMARK LIFE SCIENCES LTD, as CONSUlTANT, Retired from GLENMARK in Jan2022 Research Centre as Principal Scientist, Process Research (bulk actives) at Mahape, Navi Mumbai, India. Total Industry exp 32 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 Open superstar worlddrugtracker. His New Drug Approvals, Green Chemistry International, All about drugs, Eurekamoments, Organic spectroscopy international,
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and implementation them on commercial scale over a 32 PLUS year tenure till date Feb 2023, Around 35 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 100 million plus hits on Google, 2.5 lakh plus connections on all networking sites, 100 Lakh plus views on dozen plus blogs, 227 countries, 7 continents, He makes himself available to all, contact him on +91 9323115463, email amcrasto@gmail.com, Twitter, @amcrasto , He lives and will die for his family, 90% paralysis cannot kill his soul., Notably he has 38 lakh plus views on New Drug Approvals Blog in 227 countries......https://newdrugapprovals.wordpress.com/ , He appreciates the help he gets from one and all, Friends, Family, Glenmark, Readers, Wellwishers, Doctors, Drug authorities, His Contacts, Physiotherapist, etc
He has total of 32 International and Indian awards
Molecular Formula: C13H16N2O2Molecular Weight: 232.28Percent Composition: C 67.22%, H 6.94%, N 12.06%, O 13.78%
Literature References: A hormone of the pineal gland, also produced by extra-pineal tissues, that lightens skin color in amphibians by reversing the darkening effect of MSH, q.v. Melatonin has been postulated as the mediator of photic-induced antigonadotrophic activity in photoperiodic mammals and has also been shown to be involved in thermoregulation in some ectotherms and in affecting locomotor activity rhythms in sparrows. Isoln from the pineal glands of beef cattle: Lerner et al.,J. Am. Chem. Soc.80, 2587 (1958); Wurtman et al.,Science141, 277 (1963). Structure: Lerner et al.,J. Am. Chem. Soc.81, 6084 (1959). Crystal and molecular structure: A. Wakahara, Chem. Lett.1972, 1139. Synthesis from 5-methoxyindole as starting material by two different routes: Szmuszkovicz et al.,J. Org. Chem.25, 857 (1960). Biochemical role of melatonin: Chem. Eng. News45, 40 (May 1, 1967). Pharmacological studies: Barchas et al.,Nature214, 919 (1967). Identification of antigonadal action sites in mouse brain: J. D. Glass, G. R. Lynch, Science214, 821 (1981). Binding studies in human hypothalamus: S. M. Reppert et al.,Science242, 78 (1988). Efficacy in control of estrus in red deer: G. W. Asher, Anim. Reprod. Sci.22, 145 (1990). Reviews: M. K. Vaughn, Int. J. Rev. Physiol.24, 41-95 (1981); D. C.Klein et al.,Life Sci.28, 1975-1986 (1981). Book: Advan. Biosci.vol. 29, N. Birau, W. Schlott, Eds. (Pergamon Press, New York, 1981) 420 pp. Review of etiological role in clinical disease: A. Miles, D. Philbrick, Crit. Rev. Clin. Lab. Sci.25, 231-253 (1987); in psychiatric disorders: eidem,Biol. Psychiatry23, 405-425 (1988).Properties: Pale yellow leaflets from benzene, mp 116-118°. uv max: 223, 278 nm (e 27550, 6300).Melting point: mp 116-118°Absorption maximum: uv max: 223, 278 nm (e 27550, 6300)Therap-Cat-Vet: Control of estrus.
Melatonin is a hormone primarily released by the pineal gland that regulates the sleep–wake cycle.[3][4] As a dietary supplement, it is often used for the short-term treatment of insomnia, such as from jet lag or shift work, and is typically taken by mouth.[5][6][7] Evidence of its benefit for this use, however, is not strong.[8] A 2017 review found that sleep onset occurred six minutes faster with use, but found no change in total time asleep.[6] The melatonin receptor agonist medication ramelteon may work as well as melatonin supplements,[6] at greater cost but with different adverse effects, for some sleep conditions.[9]
Melatonin was discovered in 1958.[3] It is sold over the counter in Canada and the United States;[10][13] in the United Kingdom, it is a prescription-only medication.[7] It is not approved by the US Food and Drug Administration (FDA) for any medical use.[10] In Australia and the European Union, it is indicated for difficulty sleeping in people over the age of 54.[20][11] In the European Union, it is indicated for the treatment of insomnia in children and adolescents.[12] It was approved for medical use in the European Union in 2007.[11]
Chemical Synthesis of Melatonin The methods for the chemical synthesis of melatonin are generally not so complicated and do not involve more than three steps of conversion. Three synthesis reactions of melatonin from primary literatures are shown below;
Reaction 1
In 1958 melatonin was first isolated and characterised by A.B.Lerner. It was know as one of a substituted 5-hydroxyindole derivative in the pineal gland that could lighten pigment cells. It had not been know to exist in biological tissue although it had been isolated as a urinary excretion product in rats after administration of 5-hydroxytryptamine. Melatonin or N-acetyl-5-methoxytryptamine (40 mg) was prepared by reducing 100 mg of 5-methoxyindole-3-acetonitrile with 160 mg of sodium and 2 ml of ethanol. Then the product was acetylated with 4 ml of both glacial acetic acid and acetic anhydride at 100 oC for 1 minute. Purification was achieved by countercerrent distribution and silicic acid chromatography.
Reaction 2
5-Methoxytryptamine hydrochloride (1g, 4.75 mmole) was dissolved in pyridine (10 ml) and acetic anhydride (10 ml) and kept overnight at 20 oC. The solution was poured onto iced, neutralised with dilute hydrochloric acid and extracted with chloroform (2×25 ml). The combined extracts were washed with water, dried in MgSO4 and evaporated to afford a liquid of N,N diacetyltryptamine derivative. The liquid was then poured into water (50 ml) and extracted with chlroform (2×25 ml). The combined organic layers were washed with water (25 ml), dried in MgSO4 and evaporated to dryness. The residual solid crystallised from benzene to afford melatonin 819 mg, 80% yield.
Reaction 3
The more reactive indoles (1a-1d) were alkylated at the 3 position by reaction with nitroethene generated in situ by thermolysis of nitroethyl acetate. The nitroethyl acetate used for this purpose was prepared by acetylation of nitroethanol with acetic anhydride using NaOAc as a catalyst. These conditions constitute a substantial improvement of the overal yield of the reation. Reduction of the nitroethylated indoles (2a-d) by hydrogenation over PtO2, followed by acetylation fo the resluting tryptamines with acetic anhydride-pyridine completed the synthesis of melatonin and its derivatives (4a-d).
Biological Synthesis and Metabolism of Melatonin
The biosynthesis of melatonin (Fig.1) is initiated by the uptake of the essential amino acid tryptophan into pineal parenchymal cells. Tryptophan is the least abundant of essential amino acids in normal diets. It is converted to another amino acid, 5-hydroxytryptophan, through the action of the enzyme tryptopahn hydroxylase and then to 5-hydroxytryptamine (serotonin) by the enzyme aromatic amino acid decarboxylase. Serotonin concentrations are higher in the pineal than in any other organ or in any brain region. They exhibit a striking diurnal rhythm remaining at a maximum level during the daylight hours and falling by more than 80% soon after the onset of darkness as the serotonin is converted to melatonin, 5-hydroxytryptophol and other methoxyindoles. Serotonin’s conversion to melatonin involves two enzymes that are characteristic of the pineal : SNAT (serotonin-N-acetyltransferase) which converts the serotonin to N-acetylserotonin, and HIOMT (hydroxyindole-O-methyltrasferase) which trasfers a methyl group from S-adenosylmethionine to the 5-hydroxyl of the N-acetylserotonin. The activities of both enzymes rise soon after the onset of darkness because of the enhanced release of norepinephrine from sympathetic neurons terminating on the pineal parenchymal cells. Another portion of the serotonin liberated from pineal cells after the onset of darkness is deaminated by the enzyme monoamine oxidase (MAO) and then either oxidized to form 5-hydroxyindole acetic acid or reduced to form 5-hydroxytryptophol (Fig.1). Both of these compounds are also substrates for HIOMT and can thus be converted in the pineal to 5-methoxyindole acetic acid 5-methoxytryptophol (Fig.1). The level of this latter indole, like that of melatonin, rises markedly in the pineal with the onset of darkness. Since 5-methoxytryptophol synthesis does not require the acetylation of serotonin, the nocturnal increase in pineal SNAT activity cannot be the trigger that causes pineal methoxyindole levels to rise. More likely, a single unexplained process- the intraparenchymal release of stored pineal serotonin, which then becomes accessible to both SNAT and MAO. This process ultimately controls the rates at which all three major pineal methoxyindoles are synthesized and generates the nocturnal increases in pineal melatonin and 5-methoxytryptophol. The proportion of available serotonin acetylated at any particular time of day or night depends on the relative activities of pineal SNAT and MAO at that time. The rates of methylation of all three 5-hydroxyindoles formed from pinela serotonin depends on HIOMT activity.Fig.1 Biosynthesis of pineal methoxyindoles from serotonin
Serotonin may be either acetylated to form N-acetylserotonin through the action of the enzyme serotonin-N-acetyltransferase (SNAT), or oxidatively deaminated by monoamine oxidase (MAO) to yield an unstable aldehyde. This compound is then either oxidized to 5-hydroxyindole acetic acid by the enzyme aldehyde dehydrogenase (ADH), or reduced to from 5-hydroxytryptophol by aldehyde reductase (AR). Each of these 5-hydroxyindole derivatives of serotonin is a substrate for hydroxyindole-O-methyltrasferase (HIMOT). The enzymatic trasfer of a methyl group from S-adenosylmethionine to these hydroxyindoles yields melatonin (5-hydroxy-N-acetyltryptamine), 5-methoxyindole acetic acid and 5-methoxytryptophol respectively. Pineal serotonin is synthesized from the essential amino acid tryptophan by 5-hydroxylation folloed by decarboxylation. The first step in ths enzymic sequence is catalysed by tryptophan hydroxylase. The second step is catalysed by aromatic L-amino acid decarboxylase.
Medical uses
In the European Union it is indicated for the treatment of insomnia in children and adolescents aged 2–18 with autism spectrum disorder (ASD) and / or Smith–Magenis syndrome, where sleep hygiene measures have been insufficient[12] and for monotherapy for the short-term treatment of primary insomnia characterized by poor quality of sleep in people who are aged 55 or over.[11]
Sleep disorders
Positions on the benefits of melatonin for insomnia are mixed.[8] An Agency for Healthcare Research and Quality (AHRQ) review from 2015 stated that evidence of benefit in the general population was unclear.[8] A review from 2017, found a modest effect on time until onset of sleep.[3] Another review from 2017 put this decrease at six minutes to sleep onset but found no difference in total sleep time.[6] Melatonin may also be useful in delayed sleep phase syndrome.[3] Melatonin appears to work as well as ramelteon but costs less.[6]
A 2020 Cochrane review found no evidence that melatonin helped sleep problems in people with moderate to severe dementia due to Alzheimer’s disease.[26] A 2019 review found that while melatonin may improve sleep in minimal cognitive impairment, after the onset of Alzheimer’s it has little to no effect.[27] Melatonin may, however, help with sundowning.[28]
Jet lag and shift work
Melatonin is known to reduce jet lag, especially in eastward travel. If the time it is taken is not correct, however, it can instead delay adaption.[29]
Melatonin appears to have limited use against the sleep problems of people who work shift work.[30] Tentative evidence suggests that it increases the length of time people are able to sleep.[30]
Adverse effects
Melatonin appears to cause very few side effects as tested in the short term, up to three months, at low doses.[clarification needed] Two systematic reviews found no adverse effects of exogenous melatonin in several clinical trials and comparative trials found the adverse effects headaches, dizziness, nausea, and drowsiness were reported about equally for both melatonin and placebo.[31][32] Prolonged-release melatonin is safe with long-term use of up to 12 months.[33] Although not recommended for long term use beyond this, low-dose melatonin is generally safer, and a better alternative, than many prescription and over the counter sleep aids if a sleeping medication must be used for an extended period of time. Low-doses of melatonin are usually sufficient to produce a hypnotic effect in most people. Higher doses do not appear to result in a stronger effect, but instead appear to cause drowsiness for a longer period of time.[34]
In those taking warfarin, some evidence suggests there may exist a potentiating drug interaction, increasing the anticoagulant effect of warfarin and the risk of bleeding.[41]
Functions
When eyes receive light from the sun, the pineal gland’s production of melatonin is inhibited and the hormones produced keep the human awake. When the eyes do not receive light, melatonin is produced in the pineal gland and the human becomes tired.
Circadian rhythm
In animals, melatonin plays an important role in the regulation of sleep–wake cycles.[42] Human infants’ melatonin levels become regular in about the third month after birth, with the highest levels measured between midnight and 8:00 am.[43] Human melatonin production decreases as a person ages.[44] Also, as children become teenagers, the nightly schedule of melatonin release is delayed, leading to later sleeping and waking times.[45]
Antioxidant
Melatonin was first reported as a potent antioxidant and free radical scavenger in 1993.[46] In vitro, melatonin acts as a direct scavenger of oxygen radicals and reactive nitrogen species including OH•, O2−•, and NO•.[47][48] In plants, melatonin works with other antioxidants to improve the overall effectiveness of each antioxidant.[48] Melatonin has been proven to be twice as active as vitamin E, believed to be the most effective lipophilic antioxidant.[49] Via signal transduction through melatonin receptors, melatonin promotes the expression of antioxidant enzymes such as superoxide dismutase, glutathione peroxidase, glutathione reductase, and catalase.[50][51]
Melatonin occurs at high concentrations within mitochondrial fluid which greatly exceed the plasma concentration of melatonin.[52][53][54] Due to its capacity for free radical scavenging, indirect effects on the expression of antioxidant enzymes, and its significant concentrations within mitochondria, a number of authors have indicated that melatonin has an important physiological function as a mitochondrial antioxidant.[50][52][53][54][55]
The melatonin metabolites produced via the reaction of melatonin with reactive oxygen species or reactive nitrogen species also react with and reduce free radicals.[51][55] Melatonin metabolites generated from redox reactions include cyclic 3-hydroxymelatonin, N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK), and N1-acetyl-5-methoxykynuramine (AMK).[51][55]
Immune system
While it is known that melatonin interacts with the immune system,[56][57] the details of those interactions are unclear. An antiinflammatory effect seems to be the most relevant. There have been few trials designed to judge the effectiveness of melatonin in disease treatment. Most existing data are based on small, incomplete trials. Any positive immunological effect is thought to be the result of melatonin acting on high-affinity receptors (MT1 and MT2) expressed in immunocompetent cells. In preclinical studies, melatonin may enhance cytokine production,[58] and by doing this, counteract acquired immunodeficiences. Some studies also suggest that melatonin might be useful fighting infectious disease[59] including viral, such as HIV, and bacterial infections, and potentially in the treatment of cancer.
In bacteria, protists, fungi, and plants, melatonin is synthesized indirectly with tryptophan as an intermediate product of the shikimate pathway. In these cells, synthesis starts with D-erythrose 4-phosphate and phosphoenolpyruvate, and in photosynthetic cells with carbon dioxide. The rest of the synthesising reactions are similar, but with slight variations in the last two enzymes.[62][63]
It has been hypothesized that melatonin is made in the mitochondria and chloroplasts.[64]
Mechanism
Mechanism of melatonin biosynthesis
In order to hydroxylate L-tryptophan, the cofactor tetrahydrobiopterin (THB) must first react with oxygen and the active site iron of tryptophan hydroxylase. This mechanism is not well understood, but two mechanisms have been proposed:
1. A slow transfer of one electron from the THB to O2 could produce a superoxide which could recombine with the THB radical to give 4a-peroxypterin. 4a-peroxypterin could then react with the active site iron (II) to form an iron-peroxypterin intermediate or directly transfer an oxygen atom to the iron.
2. O2 could react with the active site iron (II) first, producing iron (III) superoxide which could then react with the THB to form an iron-peroxypterin intermediate.
Iron (IV) oxide from the iron-peroxypterin intermediate is selectively attacked by a double bond to give a carbocation at the C5 position of the indole ring. A 1,2-shift of the hydrogen and then a loss of one of the two hydrogen atoms on C5 reestablishes aromaticity to furnish 5-hydroxy-L-tryptophan.[65]
A decarboxylase with cofactor pyridoxal phosphate (PLP) removes CO2 from 5-hydroxy-L-tryptophan to produce 5-hydroxytryptamine.[66] PLP forms an imine with the amino acid derivative. The amine on the pyridine is protonated and acts as an electron sink, enabling the breaking of the C-C bond and releasing CO2. Protonation of the amine from tryptophan restores the aromaticity of the pyridine ring and then imine is hydrolyzed to produce 5-hydroxytryptamine and PLP.[67]
It has been proposed that histidine residue His122 of serotonin N-acetyl transferase is the catalytic residue that deprotonates the primary amine of 5-hydroxytryptamine, which allows the lone pair on the amine to attack acetyl-CoA, forming a tetrahedral intermediate. The thiol from coenzyme A serves as a good leaving group when attacked by a general base to give N-acetylserotonin.[68]
N-acetylserotonin is methylated at the hydroxyl position by S-adenosyl methionine (SAM) to produce S-adenosyl homocysteine (SAH) and melatonin.[67][69]
Regulation
In vertebrates, melatonin secretion is regulated by activation of the beta-1 adrenergic receptor by norepinephrine.[70] Norepinephrine elevates the intracellular cAMP concentration via beta-adrenergic receptors and activates the cAMP-dependent protein kinase A (PKA). PKA phosphorylates the penultimate enzyme, the arylalkylamine N-acetyltransferase (AANAT). On exposure to (day)light, noradrenergic stimulation stops and the protein is immediately destroyed by proteasomalproteolysis.[71] Production of melatonin is again started in the evening at the point called the dim-light melatonin onset.
Blue light, principally around 460–480 nm, suppresses melatonin biosynthesis,[72] proportional to the light intensity and length of exposure. Until recent history, humans in temperate climates were exposed to few hours of (blue) daylight in the winter; their fires gave predominantly yellow light.[citation needed] The incandescent light bulb widely used in the 20th century produced relatively little blue light.[73] Light containing only wavelengths greater than 530 nm does not suppress melatonin in bright-light conditions.[74] Wearing glasses that block blue light in the hours before bedtime may decrease melatonin loss. Use of blue-blocking goggles the last hours before bedtime has also been advised for people who need to adjust to an earlier bedtime, as melatonin promotes sleepiness.[75]
When used several hours before sleep according to the phase response curve for melatonin in humans, small amounts (0.3 mg[77]) of melatonin shift the circadian clock earlier, thus promoting earlier sleep onset and morning awakening.[78] Melatonin is rapidly absorbed and distributed, reaching peak plasma concentrations after 60 minutes of administration, and is then eliminated.[61] Melatonin has a half life of 35–50 minutes.[79] In humans, 90% of orally administered exogenous melatonin is cleared in a single passage through the liver, a small amount is excreted in urine, and a small amount is found in saliva.[5] The bioavalibility of melatonin is between 10 and 50%.[61]
Melatonin is metabolized in the liver by cytochrome P450 enzyme CYP1A2 to 6-hydroxymelatonin. Metabolites are conjugated with sulfuric acid or glucuronic acid for excretion in the urine. 5% of melatonin is excreted in the urine as the unchanged drug.[61]
Some of the metabolites formed via the reaction of melatonin with a free radical include cyclic 3-hydroxymelatonin, N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK), and N1-acetyl-5-methoxykynuramine (AMK).[51][55]
In 1958, dermatology professor Aaron B. Lerner and colleagues at Yale University, in the hope that a substance from the pineal might be useful in treating skin diseases, isolated the hormone from bovine pineal gland extracts and named it melatonin.[85] In the mid-70s Lynch et al. demonstrated that the production of melatonin exhibits a circadian rhythm in human pineal glands.[86]
The discovery that melatonin is an antioxidant was made in 1993.[87] The first patent for its use as a low-dose sleep aid was granted to Richard Wurtman at MIT in 1995.[88] Around the same time, the hormone got a lot of press as a possible treatment for many illnesses.[89]The New England Journal of Medicine editorialized in 2000: “With these recent careful and precise observations in blind persons, the true potential of melatonin is becoming evident, and the importance of the timing of treatment is becoming clear.”[90]
It was approved for medical use in the European Union in 2007.[11]
Other animals
In vertebrates, melatonin is produced in darkness, thus usually at night, by the pineal gland, a small endocrine gland[91] located in the center of the brain but outside the blood–brain barrier. Light/dark information reaches the suprachiasmatic nuclei from retinal photosensitive ganglion cells of the eyes[92][93] rather than the melatonin signal (as was once postulated). Known as “the hormone of darkness”, the onset of melatonin at dusk promotes activity in nocturnal (night-active) animals and sleep in diurnal ones including humans.
Many animals use the variation in duration of melatonin production each day as a seasonal clock.[94] In animals including humans,[95] the profile of melatonin synthesis and secretion is affected by the variable duration of night in summer as compared to winter. The change in duration of secretion thus serves as a biological signal for the organization of daylength-dependent (photoperiodic) seasonal functions such as reproduction, behavior, coat growth, and camouflage coloring in seasonal animals.[95] In seasonal breeders that do not have long gestation periods and that mate during longer daylight hours, the melatonin signal controls the seasonal variation in their sexual physiology, and similar physiological effects can be induced by exogenous melatonin in animals including mynah birds[96] and hamsters.[97] Melatonin can suppress libido by inhibiting secretion of luteinizing hormone and follicle-stimulating hormone from the anterior pituitary gland, especially in mammals that have a breeding season when daylight hours are long. The reproduction of long-day breeders is repressed by melatonin and the reproduction of short-day breeders is stimulated by melatonin.
During the night, melatonin regulates leptin, lowering its levels.
Cetaceans have lost all the genes for melatonin synthesis as well as those for melatonin receptors.[98] This is thought to be related to their unihemispheric sleep pattern (one brain hemisphere at a time). Similar trends have been found in sirenians.[98]
Plants
Until its identification in plants in 1987, melatonin was for decades thought to be primarily an animal neurohormone. When melatonin was identified in coffee extracts in the 1970s, it was believed to be a byproduct of the extraction process. Subsequently, however, melatonin has been found in all plants that have been investigated. It is present in all the different parts of plants, including leaves, stems, roots, fruits, and seeds, in varying proportions.[19][99] Melatonin concentrations differ not only among plant species, but also between varieties of the same species depending on the agronomic growing conditions, varying from picograms to several micrograms per gram.[63][100] Notably high melatonin concentrations have been measured in popular beverages such as coffee, tea, wine, and beer, and crops including corn, rice, wheat, barley, and oats.[19] In some common foods and beverages, including coffee[19] and walnuts,[101] the concentration of melatonin has been estimated or measured to be sufficiently high to raise the blood level of melatonin above daytime baseline values.
Although a role for melatonin as a plant hormone has not been clearly established, its involvement in processes such as growth and photosynthesis is well established. Only limited evidence of endogenous circadian rhythms in melatonin levels has been demonstrated in some plant species and no membrane-bound receptors analogous to those known in animals have been described. Rather, melatonin performs important roles in plants as a growth regulator, as well as environmental stress protector. It is synthesized in plants when they are exposed to both biological stresses, for example, fungal infection, and nonbiological stresses such as extremes of temperature, toxins, increased soil salinity, drought, etc.[63][102][103]
Occurrence
Dietary supplement
Melatonin is categorized by the US Food and Drug Administration (FDA) as a dietary supplement, and is sold over-the-counter in both the US and Canada.[5] FDA regulations applying to medications are not applicable to melatonin,[15] though the FDA has found false claims that it cures cancer.[104] As melatonin may cause harm in combination with certain medications or in the case of certain disorders, a doctor or pharmacist should be consulted before making a decision to take melatonin.[29] In many countries, melatonin is recognized as a neurohormone and it cannot be sold over-the-counter.[105]
Food products
Naturally-occurring melatonin has been reported in foods including tart cherries to about 0.17–13.46 ng/g,[106] bananas and grapes, rice and cereals, herbs, plums,[107] olive oil, wine[108] and beer. When birds ingest melatonin-rich plant feed, such as rice, the melatonin binds to melatonin receptors in their brains.[109] When humans consume foods rich in melatonin, such as banana, pineapple, and orange, the blood levels of melatonin increase significantly.[110]
Beverages and snacks containing melatonin were being sold in grocery stores, convenience stores, and clubs in May 2011.[111] The FDA considered whether these food products could continue to be sold with the label “dietary supplements”. On 13 January 2010, it issued a Warning Letter to Innovative Beverage, creators of several beverages marketed as drinks, stating that melatonin, while legal as a dietary supplement, was not approved as a food additive.[112] A different company selling a melatonin-containing beverage received a warning letter in 2015.[113]
Commercial availability
Immediate-release melatonin is not tightly regulated in countries where it is available as an over-the-counter medication. It is available in doses from less than half a milligram to 5 mg or more. Immediate-release formulations cause blood levels of melatonin to reach their peak in about an hour. The hormone may be administered orally, as capsules, gummies, tablets, or liquids. It is also available for use sublingually, or as transdermal patches.[medical citation needed]
Formerly, melatonin was derived from animal pineal tissue, such as bovine. It is now synthetic, which limits the risk of contamination or the means of transmitting infectious material.[15][114]
Melatonin is the most popular over-the-counter sleep remedy in the US, resulting in sales in excess of US$400 million during 2017.[115]
Research
A bottle of melatonin tablets. Melatonin is available in timed-release and in liquid forms.
Various uses and effects of melatonin have been studied. A 2015 review of studies of melatonin in tinnitus found the quality of evidence low, but not entirely without promise.[116]
Headaches
Tentative evidence shows melatonin may help reduce some types of headaches including cluster and hypnic headaches.[117][118]
Cancer
A 2013 review by the National Cancer Institutes found evidence for use to be inconclusive.[119] A 2005 review of unblinded clinical trials found a reduced rate of death, but that blinded and independently conducted randomized controlled trials are needed.[120]
Protection from radiation
Both animal[121] and human[122][123][124] studies have shown melatonin to protect against radiation-induced cellular damage. Melatonin and its metabolites protect organisms from oxidative stress by scavenging reactive oxygen species which are generated during exposure.[125] Nearly 70% of biological damage caused by ionizing radiation is estimated to be attributable to the creation of free radicals, especially the hydroxyl radical that attacks DNA, proteins, and cellular membranes. Melatonin has been described as a broadly protective, readily available, and orally self-administered antioxidant that is without known, major side effects.[126]
Epilepsy
A 2016 review found no beneficial role of melatonin in reducing seizure frequency or improving quality of life in people with epilepsy.[127]
Secondary dysmenorrhoea
A 2016 review suggested no strong evidence of melatonin compared to placebo for dysmenorrhoea secondary to endometriosis.[128]
Delirium
A 2016 review suggested no clear evidence of melatonin to reduce the incidence of delirium.[129]
Gastroesophageal reflux disease
A 2011 review said melatonin is effective in relieving epigastric pain and heartburn.[130]
Psychiatry
Melatonin might improve sleep in people with autism.[131] Children with autism have abnormal melatonin pathways and below-average physiological levels of melatonin.[132][133] Melatonin supplementation has been shown to improve sleep duration, sleep onset latency, and night-time awakenings.[132][134][135] However, many studies on melatonin and autism rely on self-reported levels of improvement and more rigorous research is needed.
While the packaging of melatonin often warns against use in people under 18 years of age, studies suggest that melatonin is an efficacious and safe treatment for insomnia in people with ADHD, including children. However, larger and longer studies are needed to establish long-term safety and optimal dosing.[136]
Melatonin in comparison to placebo is effective for reducing preoperative anxiety in adults when given as premedication. It may be just as effective as standard treatment with midazolam in reducing preoperative anxiety. Melatonin may also reduce postoperative anxiety (measured 6 hours after surgery) when compared to placebo.[137]
Some supplemental melatonin users report an increase in vivid dreaming. Extremely high doses of melatonin increased REM sleep time and dream activity in people both with and without narcolepsy.[138] Some evidence supports an antidepressant effect.[139]
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^ Jump up to:abc Reiter RJ, Rosales-Corral S, Tan DX, Jou MJ, Galano A, Xu B (November 2017). “Melatonin as a mitochondria-targeted antioxidant: one of evolution’s best ideas”. Cellular and Molecular Life Sciences. 74 (21): 3863–3881. doi:10.1007/s00018-017-2609-7. PMID28864909. S2CID23820389. melatonin is specifically targeted to the mitochondria where it seems to function as an apex antioxidant … The measurement of the subcellular distribution of melatonin has shown that the concentration of this indole in the mitochondria greatly exceeds that in the blood.
^ Jump up to:abc Reiter RJ, Mayo JC, Tan DX, Sainz RM, Alatorre-Jimenez M, Qin L (October 2016). “Melatonin as an antioxidant: under promises but over delivers”. Journal of Pineal Research. 61 (3): 253–78. doi:10.1111/jpi.12360. PMID27500468. S2CID35435683. There is credible evidence to suggest that melatonin should be classified as a mitochondria-targeted antioxidant.
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With the development of atomic science, radiation therapy such as cobalt hexahydrate, linear accelerator, and electron beam has become one of the main methods of cancer treatment. However, traditional photon or electron therapy is limited by the physical conditions of the radiation itself. While killing the tumor cells, it also causes damage to a large number of normal tissues on the beam path. In addition, due to the sensitivity of tumor cells to radiation, traditional radiation therapy For the more radiation-resistant malignant tumors (such as: glioblastoma multiforme, melanoma), the treatment effect is often poor.
In order to reduce the radiation damage of normal tissues around the tumor, the concept of target treatment in chemotherapy has been applied to radiation therapy; and for tumor cells with high radiation resistance, it is currently actively developing with high relative biological effects (relative Biological effectiveness, RBE) radiation sources, such as proton therapy, heavy particle therapy, neutron capture therapy. Among them, neutron capture therapy combines the above two concepts, such as boron neutron capture therapy, by the specific agglomeration of boron-containing drugs in tumor cells, combined with precise neutron beam regulation, providing better radiation than traditional radiation. Cancer treatment options.
Boron Neutron Capture Therapy (BNCT) is a high-capture cross-section of thermal neutrons using boron-containing ( 10 B) drugs, with 10 B(n,α) 7 Li neutron capture and nuclear splitting reactions. Two heavy charged particles of 4 He and 7 Li are produced. The average energy of the two charged particles is about 2.33 MeV, which has high linear energy transfer (LET) and short range characteristics. The linear energy transfer and range of α particles are 150 keV/μm and 8 μm, respectively, while the 7 Li heavy particles are For 175 keV/μm, 5 μm, the total range of the two particles is equivalent to a cell size, so the radiation damage caused to the organism can be limited to the cell level, when the boron-containing drug is selectively aggregated in the tumor cells, with appropriate The sub-radiation source can achieve the purpose of locally killing tumor cells without causing too much damage to normal tissues.
Since the effectiveness of boron neutron capture therapy depends on the concentration of boron-containing drugs in the tumor cell position and the number of thermal neutrons, it is also called binary cancer therapy; thus, in addition to the development of neutron sources, The development of boron-containing drugs plays an important role in the study of boron neutron capture therapy.
4-( 10 B)dihydroxyboryl-L-phenylalanine (4-( 10 B)borono-L-phenylalanine, L- 10 BPA) is currently known to be able to utilize boron neutron capture therapy (boron neutron capture therapy) , BNCT) An important boron-containing drug for the treatment of cancer.
Therefore, various synthetic methods of L-BPA have been developed. As shown in the following formula (A), the prior art L-BPA synthesis method includes two methods of forming a bond (a) and a bond (b):
Among them, the method for synthesizing L-BPA by forming the bond (a) is to try to introduce a substituent containing a dihydroxylboryl group or a borono group into the skeleton of the phenylalanine, thereby the pair of the amide substituent. The position forms a carbon-boron bond to produce L-BPA.
J. Org. Chem. 1998, 63, 8019 discloses a method for the cross-coupling reaction of (S)-4-iodophenylalanine with a diboron compound by palladium-catalyzed amine end treatment. Amine-protected (S)-4-iodophenylalanine (eg (S)-N-tert-butoxycarbonyl-4-iodophenylalanine ((S)-N-Boc-4-) Iodophenylalanine)) is prepared by cross-coupling with a diboron compound such as bis(pinacolato diboron) to give (S)-N-tert-butoxycarbonyl-4-pentanoylboryl phenylalanine The amine-terminated (S)-4-boranyl ester phenylalanine of the acid ((S)-N-Boc-4-pinacolatoborono phenylalanine); afterwards, the protecting group on the amine end and the boronic end are removed. The above substituents complete the preparation of L-BPA.
However, since the selected 10 B-doped divaleryl diboron is not a commercially available compound, this method requires additional pretreatment of the preparation of the borating agent, resulting in a high process complexity and a long time consuming process. It is impossible to prepare a high yield of L-BPA. In addition, the carboxylic acid group of the protected (S)-4-iodophenylalanine at the amine end needs to be protected by a substituent to form a benzyl ester group to increase the process yield to 88%; however, The preparation of L-BPA in this manner also requires an additional step of deprotecting the carboxylic acid group, which in turn increases the process complexity of L-BPA.
Accordingly, the method provided in this document not only involves pre-treatment of the preparation of the borating agent, but also requires a large amount of process time and synthesis steps to complete the steps of protecting and deprotecting the carboxylic acid group, and is not advantageous as an industry. The main method of synthesizing L-BPA.
On the other hand, a method for synthesizing L-BPA by forming a bond (b) is a coupling reaction of an amino acid with a boron-containing benzyl fragment or a boron-containing benzaldehyde fragment. To synthesize L-BPA. Biosci. Biotech. Biochem. 1996, 60, 683 discloses an enantioselective synthesis of L-BPA which gives the hands of a cyclic ethers of boronic acid and L-proline The chiral derivatives from L-valine are subjected to a coupling reaction to produce L-BPA. However, this method requires the formation of a cyclic ether compound of boric acid from 4-boronobenzylbromide, followed by a coupling reaction with a chiral derivative of L-proline, and in the latter stage. The amino acid undergoes an undesired racemization in the synthesis step, so that the method requires an enzymatic resolution step to reduce the yield to obtain L-BPA having a certain optical purity.
Accordingly, the method provided in the literature still includes the steps of pretreatment of the preparation of the borating agent and post-treatment of the enzymatic resolution, so that the process involved in the method is complicated and takes a long time, and cannot be obtained. High yield of L-BPA.
In addition, L- 10 BPA (4-( 10 B)borono-L-phenylalanine, 4-( 10 B)dihydroxyboryl-L-phenylalanine) containing 10 boron is currently known to accumulate in tumor cells. The key factor is to use the thermal neutron beam to irradiate the boron element accumulated in the tumor cells to kill the tumor cells by capturing the high-energy particles generated by the reaction, thereby achieving the purpose of treating cancer. Therefore, 10 boron can promote the treatment of L- 10 BPA by boron neutron capture treatment.
However, the boron element present in nature contains about 19.9% of 10 boron and about 80.1% of 11 boron. Therefore, many researchers are still actively developing methods that can be applied to the synthesis of L-BPA, especially for the synthesis of 10- boron-rich L-BPA.
J.Org.Chem.1998,63,8019 additionally provides a method of synthesizing 10 boronated agents, since the method involves multiple steps, it is easy to greatly reduce the boron content of 1010 boron enriched material in the manufacturing process. Therefore, the method provided in this document is not suitable for the synthesis of 10- boron-rich L-BPA.
Another example is the Biosci.Biotech.Biochem.1996,60,683, before the enzymatic resolution step is not performed, the method provided by the articles could not be obtained with a certain L-BPA optical purity; 10 and the method for preparing boronated agents when also relates to multi-step, resulting in conversion of boron-rich material 10 occurs during the manufacturing process. Therefore, the method provided in this document is also not suitable for the synthesis of 10- boron-rich L-BPA.
Furthermore, Bull. Chem. Soc. Jpn. 2000, 73, 231 discloses the use of palladium to catalyze 4-iodo-L-phenylalanine with 4,4,5,5-tetramethyl-1,3,2 A method in which a dioxonium pentoxide (common name: pinacolborane) is subjected to a coupling reaction. However, this document does not mention how to prepare articles 10 boron enriched L-BPA using this method, and 4,4,5,5-tetramethyl-1,3,2-dioxaborolane not a commercial 10 The compounds available in the literature are not suitable for the synthesis of 10- boron-rich L-BPA.
In addition, Synlett. 1996, 167 discloses a method for coupling a iodophenylborate with a zinc derivative of L-serine zinc derivatives, which involves first preparing phenyl iodoborate. The ester and the preparation of a zinc derivative of L-type serine acid, etc., result in a lower yield of the produced L-BPA. In addition, since the 10- boron-rich triiodide 10 boron and 1,3-diphenylpropane-1,3-diol selected for this method are not commercially available compounds, the methods provided in this document are also provided. Still not suitable for the synthesis of 10- boron-rich L-BPA.
SYN
Repub. Korean Kongkae Taeho Kongbo, 2018060319,
PAPER
Research and Development in Neutron Capture Therapy, Proceedings of the International Congress on Neutron Capture Therapy, 10th, Essen, Germany, Sept. 8-13, 2002 (2002), 1-8.
PAPER
European Journal of Pharmaceutical Sciences (2003), 18(2), 155-163
Before preparing (S)-N-tert-butoxycarbonyl-4-dihydroxyborylphenylalanine from (S)-N-tert-butoxycarbonyl-4-iodophenylalanine, it is necessary to reveal Process for preparing (S)-N-tert-butoxycarbonyl-4-iodophenylalanine by using (S)-4-iodophenylalanine as a starting material and a process for preparing 10 tributyl borate with 10 boric acid.
1. Preparation of (S)-N-tert-butoxycarbonyl-4-iodophenylalanine from (S)-4-iodophenylalanine
Please refer to the following reaction formula I, which is (S)-4-iodophenylalanine in a solvent of 1,4-dioxane (1,4-dioxane) and water (H 2 O) with hydrogen peroxide. Sodium (NaOH) and di-tert-butyl dicarbonate (Boc 2 O) are reacted to obtain a chemical reaction formula of (S)-N-tert-butoxycarbonyl-4-iodophenylalanine.
In the preparation process, two reaction vessels were selected for the reaction.
The specific operation process is as follows:
1. Set up a reaction using a 3L three-neck bottle.
2. (S)-4-iodo-L-phenylalanine (200.00 g, 687.10 mmol, 1.00 eq) was added to the reaction system.
3. Add 1,4-dioxane (1.00 L) and water (1.00 L) to the reaction system, respectively.
4. Sodium hydroxide (68.71 g, 1.72 mol, 2.50 eq) was added to the reaction system, the solution gradually became clear, and the temperature rose slightly to 19 °C.
5. When the system is cooled to 0-10 ° C, di-tert-butyl dicarbonate (254.93 g, 1.17 mol, 268.35 mL, 1.70 eq) is added to the reaction system, and the temperature of the reaction system is naturally raised to 10 to 30 ° C and Stir at room temperature (about 30 ° C) for 8 hours.
6. The reaction was detected using high performance liquid chromatography (HPLC) until the starting of the reaction.
7. The temperature of the control system is less than 40 ° C, and the 1,4-dioxane in the reaction solution is concentrated.
8. The reaction system was lowered to room temperature (about 25 ° C), 100 mL of water was added, and the pH was adjusted to 1.8-2 with hydrochloric acid (2M (ie, molarity, M)).
9. Extract three times with ethyl acetate (2 L).
10. Combine the organic phases and wash twice with saturated brine (1 L).
11. The organic phase was dried over sodium sulfate (200 g).
12. Continue drying in an oven (40-45 ° C) to give (S)-N-tert-butoxycarbonyl-4-iodo-L-phenylalanine (250.00 g, 626.28 mmol, HPLC analysis, yield 93.00 %, purity 98%).
The prepared (S) -N- tert-butoxycarbonyl-4-iodo-phenylalanine was -L- Hydrogen 1 nuclear magnetic resonance spectrum analysis (1 HNMR) as follows:
Second, tributyl borate 10 was prepared from boronic acid 10
See the following reaction formulas II, 10 as boric acid (H 2 SO 4) is reacted with sulfuric acid in a solvent (butan-1-ol), and toluene (Toluene) in n-butanol, to obtain 10 tributyl borate (10 The chemical reaction formula of B(OBu) 3 ).
The specific operation process is as follows:
1. Set up a reaction device R1 using a 3L three-necked bottle, and configure a water separator on the device.
2. 10 boric acid (150.00 g, 2.46 mol, 1.00 eq) was added to the reaction R1 at room temperature (about 25 ° C).
3. Add n-butanol (1.00 L) to the reaction R1 at room temperature (about 25 ° C) and stir, and most of the boric acid cannot be dissolved.
4. Toluene (1.00 L) was added to the reaction R1 at room temperature (about 25 ° C) and stirred.
5. Concentrated sulfuric acid (4.82 g, 49.16 mmol, 2.62 mL, 0.02 eq) was added dropwise to the reaction at room temperature (about 25 ° C), at which time a large amount of solid remained undissolved.
6. The reaction system was heated to 130 ° C, and the water was continuously removed, stirred for 3.5 hours, and water (about 140 g) was formed in the water separator. The solids were all dissolved, and the solution changed from colorless to brown. .
8. Distill off most of the toluene at atmospheric pressure.
9. After most of the toluene is distilled off, the temperature of the system is lowered to 20 to 30 ° C, and the reaction liquids of the two reactions are combined, and the apparatus is changed for distillation.
10. Oil bath external temperature 108-110 ° C pump distillation under reduced pressure, Kelvin thermometer 45 ° C, distilled n-butanol.
11. Oil bath external temperature 108-110 ° C oil pump distillation under reduced pressure, the residual butanol was distilled off.
12. Oil bath external temperature 118-120 ° C oil pump vacuum distillation, Kelvin thermometer 55 ° C, began to produce products.
13. The temperature is raised to 135-140 ° C oil pump vacuum distillation, the product is completely distilled.
14. The product is obtained as a colorless liquid 10 tributyl borate (830.00g, 3.62mol, yield 73.58%).
The results of the 1 H NMR analysis of the obtained tributyl 10 borate were as follows:
Three, -N- tert-butoxycarbonyl-4-iodo-phenylalanine was prepared (S) of (S) -N- tert-butoxycarbonyl-4-hydroxy-10-yl -L- phenylalanine boron
Please refer to the following reaction formula III, which is (S)-N-tert-butoxycarbonyl-4-iodophenylalanine with tributyl 10 borate, t-butyl magnesium chloride (t-BuMgCl) and bis (2-A) yl aminoethyl) ether (BDMAEE) reaction, to produce (S) -N- tert-butoxycarbonyl group -4- (10 B) dihydroxyboryl -L- phenylalanine chemical reaction.
In the preparation process, two reaction vessels were selected for the reaction.
The specific operation process is as follows:
1. Set up a reaction using a 3L three-neck bottle.
2. Tributyl 10 borate (187.60 g, 87.98 mmol, 3.20 eq) was placed in the reaction system at room temperature (about 22 ° C).
3. Sodium hydride (20.45 g, 511.24 mmol, purity 60%, 2.00 eq) was added to the reaction system at room temperature (about 22 ° C). The reaction solution was a suspension and stirred at room temperature (about 22 ° C). 5 minutes.
4. Bis(2-methylaminoethyl)ether (327.73 g, 2.04 mol, 8.00 eq) was added to the reaction at room temperature (about 22 ° C).
5. N-tert-Butoxycarbonyl-4-iodo-L-phenylalanine (100.00 g, 255.62 mmol, 1.00 eq) was added to the reaction system at room temperature (about 22 ° C), and a large amount of solid was not dissolved.
6. Lower the temperature of the reaction system to 0-5 ° C, add t-butyl magnesium chloride (1.7 M, 1.20 L, 2.04 mol, 8.00 eq) to the reaction, control the temperature between 0-10 ° C, the dropping time is about It is 1.5 hours.
7. After the completion of the charging, the temperature of the reaction system was naturally raised to room temperature (20 to 30 ° C) and stirred at this temperature for 12 hours.
8. Using high performance liquid chromatography (HPLC) to detect about 9.00% of the remaining material.
9. When the temperature of the reaction system was lowered to -5 to 0 ° C, it was quenched by dropwise addition of 500 mL of water.
10. Lower the temperature of the system to 0-5 ° C, add methyl tert-butyl ether (500 mL) to the reaction system and adjust the pH to 2.9-3.1 (using a pH meter) with 37% HCl (about 500 mL). Exothermic, the temperature of the control system is between 0-15 °C.
11. The aqueous phase obtained by liquid separation was extracted once with methyl tert-butyl ether (500 mL), and the obtained organic phases were combined to give an organic phase of about 1.1 L.
12. Slowly add a sodium hydroxide aqueous solution (1 M, 400 mL) to the obtained organic phase, exotherm during the dropwise addition, and control the system temperature between 0-15 °C.
13. After the completion of the dropwise addition, the pH of the system was about 10, and the pH was adjusted to between 12.10 and 12.6 with an aqueous sodium hydroxide solution (4M). (measured with a pH meter)
14. Dispensing.
15. The aqueous phase 1 obtained after liquid separation was extracted once with n-butanol (500 ml) to obtain aqueous phase 2.
16. Combine the aqueous phase 2 of the two reaction vessels.
17. Adjust the pH of the aqueous phase to 2.9-3.1 with 37% HCl, stir for about 40 minutes, and precipitate a large amount of solid.
18. Filtration gave a white solid which was washed once with dichloromethane (50 mL).
19. At 25 ° C, the precipitated solid was slurried with dichloromethane (150 mL) and stirred for 10 min.
20. A white solid was filtered to give (S) -N- tert-butoxycarbonyl group -4- (10 B) dihydroxyboryl -L- phenylalanine (75.00g, 240.82mmol, by HPLC analysis, a yield of 47.11% , purity 99%).
The prepared (S) -N- tert-butoxycarbonyl group -4- (10 B) results dihydroxyboryl -L- phenylalanine 1 HNMR was as follows:
Preparation of L- 10 BPA from (S)-N-tert-Butoxycarbonyl-4-dihydroxyboryl-L-phenylalanine
See the following reaction scheme IV, which is (S) -N- tert-butoxycarbonyl group -4- (10 B) of amine end dihydroxyboryl -L- phenylalanine deprotection of the chemical reaction, to obtain L- 10 BPA.
The specific operation process is as follows:
1. Set up a reaction using a 1L three-neck bottle.
2. room temperature (20-30 deg.] C) to (S) -N- tert-butoxycarbonyl group -4- (10 B) dihydroxyboryl -L- phenylalanine (67.00g, 217.31mmol, 1.00eq) was added the reaction In the system.
3. room temperature (20-30 deg.] C) water (23.75mL) and acetone (Acetone, 420.00mL) were added dropwise to the reaction flask, stirred (S) -N- tert-butoxycarbonyl group -4- (10 B) dihydroxy Boronyl-L-phenylalanine.
4. Concentrated hydrochloric acid (23.93 g, 656.28 mmol, 23.46 mL, 3.02 eq) was added dropwise to the reaction system at room temperature (20-30 ° C). After the addition was completed, the reaction system was heated to 55-60 ° C and stirred for 4.5 hours.
5. HPLC detection until the reaction of the starting material is completed.
6. The temperature is controlled below 40 ° C, and the acetone in the reaction system is concentrated.
7. Lower the concentrated system to below 15 °C, adjust the pH of the system to about 1.5 with sodium hydroxide solution (4M) (pH meter detection), stir for 40 minutes and continue to adjust the pH of the system to 6.15 using sodium hydroxide solution (4M). ～6.25, a large amount of white solid precipitated, which was filtered to give a white solid, and rinsed with acetone (200mL).
8. Obtained as a white solid L- 10 BPA (36.00 g, 171.17 mmol, HPLC, yield 78.77%, purity 99%).
The analytical results obtained by the L- 10 BPA 1 HNMR are as follows:
Preparation of (S)-N-tert-butoxycarbonyl-4-dihydroxyboryl-L-phenylalanine from (S)-N-tert-butoxycarbonyl-4-iodophenylalanine
Please refer to the following reaction formula VII, which is a reaction of (S)-N-tert-butoxycarbonyl-4-iodophenylalanine with tributyl borate and t-butylmagnesium chloride (t-BuMgCl) to obtain (S The chemical reaction formula of -N-tert-butoxycarbonyl-4-dihydroxyboryl-L-phenylalanine.
The specific operation process is as follows:
1. Construct a reaction unit with a 250 mL three-neck bottle.
2. Tributyl borate (17.65 g, 76.68 mmol, 3.00 eq) was placed in a 250 mL reaction flask at 20-30 °C.
3. Sodium hydride (1.02 g, 25.56 mmol, 1.00 eq) was added to a 250 mL reaction vial at 20-30 °C.
4. (S)-N-tert-Butoxycarbonyl-4-iodo-L-phenylalanine (10.00 g, 25.56 mmol, 1.00 eq) was added to a 250 mL reaction vial at 20-30 °C.
5. Reduce the temperature of the reaction system to 0 ° C under nitrogen atmosphere, slowly add t-butyl magnesium chloride (1.7 M in THF, 120 mL, 8.00 eq) to the reaction, the dropping time is about 30 minutes, and the control temperature is 0. Between °C and 10 °C.
Stir at 20.20 ~ 30 ° C for 20 hours.
7. HPLC detection of the basic reaction of the raw materials, leaving only about 0.7% of the raw materials.
8. At a temperature of 0 ° C, 5 mL of water was added dropwise to the reaction to quench it. After complete quenching, stirring was continued for 10 minutes.
9. Cool down to 0 ° C, add methyl tert-butyl ether (50 mL) to the reaction and adjust the pH to 3 with 37% HCl (about 50 mL) (detected with a pH meter), adjust the pH during the process to exotherm, control the temperature at 0 Between °C and 15 °C.
12. The aqueous phase obtained by liquid separation was extracted once with methyl t-butyl ether (50 mL) and the organic phases were combined.
12. Add NaOH solution (1M, 55mL) to the obtained organic phase to adjust the pH to between 12.10-12.6. The process is exothermic and the temperature is controlled between 0 °C and 15 °C.
13. Liquid separation, the obtained aqueous phase was extracted once with n-butanol (50 mL), and most of the impurities were extracted and removed.
14. The aqueous phase obtained by liquid separation was adjusted to pH 3 with 37% HCl and stirred for about 30 minutes to precipitate a white solid.
15. Filtration gave a white solid which was washed once with dichloromethane (50 mL).
16. The precipitated solid was slurried with 25 mL of dichloromethane at 25 ° C and stirred for 10 minutes.
Please continue to refer to Reaction Scheme VII. The specific operation process is as follows:
1. Construct a reaction unit with a 250 mL three-neck bottle.
2. Tributyl borate (8.82 g, 38.34 mmol, 3.00 eq) was added to a 250 mL reaction vial at 20-30 °C.
3. Sodium hydride (511.25 mg, 12.78 mmol, 1.00 eq) was added to a 250 mL reaction vial at 20-30 °C.
4. (S)-N-tert-Butoxycarbonyl-4-iodo-L-phenylalanine (5.00 g, 12.78 mmol, 1.00 eq) was added to a 250 mL reaction vial at 20-30 °C.
5. The temperature of the reaction system was lowered to 0 ° C under nitrogen atmosphere, and t-butyl magnesium chloride (1.7 M in THF, 60 mL, 8.00 eq) was added dropwise to the reaction, the dropwise addition time was about 30 minutes, and the control temperature was 0 ° C. -10 ° C between.
Stir at 6.20 ~ 30 ° C for 22 hours.
7. HPLC detection of the raw material reaction is completed.
8. At a temperature of 0 ° C, 2.5 mL of water was added dropwise to the reaction to quench it. After complete quenching, stirring was continued for 10 minutes.
9. Cool down to 0 ° C, add methyl tert-butyl ether (25 mL) to the reaction and adjust the pH to 3 with 37% HCl (about 25 mL) (detected with a pH meter), adjust the pH during the process to exotherm, control the temperature at 0 Between °C and 15 °C.
12. The aqueous phase obtained by liquid separation was extracted once with methyl t-butyl ether (25 mL) and the organic phases were combined.
12. Add NaOH solution (1M, 30mL) to the obtained organic phase to adjust the pH to between 12.10-12.6. The process is exothermic and the temperature is controlled between 0 °C and 15 °C.
13. Liquid separation, the obtained aqueous phase was extracted once with n-butanol (25 ml), and most of the impurities were extracted and removed.
14. The aqueous phase obtained by liquid separation was adjusted to pH 3 with 37% HCl and stirred for about 30 minutes to precipitate a white solid.
15. Filtration gave a white solid which was washed once with dichloromethane (25 mL).
16. The precipitated solid was slurried with 15 mL of dichloromethane at 25 ° C and stirred for 10 minutes.
17. Filtration gave (S)-N-tert-butoxycarbonyl-4-dihydroxyboryl-L-phenylalanine (3.4 g, obtained by HPLC, yield: 85.26%, purity 98%).
Bis(2-methylaminoethyl)ether is a complexing agent for Mg, which can reduce the occurrence of side reactions in the reaction. The reactions of Examples 6 and 7 were carried out without adding bis(2-methylaminoethyl)ether. The analysis showed that the iodine impurity in the reaction of Example 6 was about 17%, and the iodine impurity in the reaction of Example 7 was observed. About 28%. Therefore, it has been proved from the side that the addition of bis(2-methylaminoethyl)ether can protect the reaction from reducing iodine.
The BPA or 10 BPA obtained in the above examples were analyzed by chiral HPLC, and the ratio of the L-enantiomer to the D-enantiomer was 100:0.
The boron-containing drug L-BPA for neutron capture therapy disclosed in the present invention is not limited to the contents described in the above examples. The above-mentioned embodiments are only examples for convenience of description, and the scope of the claims should be determined by the claims.
The preparation of the compound 3- (1- {3- [5- (1-Methyl-piperidin-4-ylmethoxy) -pyrimidin-2-yl] -benzyl} -6-oxo-1,6-dihydro-pyridazin-3 -yl) -benzonitrile (“A257”) takes place analogously to the following scheme
40.1 17.7 g (67.8 mmol) triphenyl are added to a suspension of 13.0 g (56.5 mmol) 3- (5-hydroxypyrimidin-2-yl) -benzoic acid methyl ester and 13.4 g (62.1 mmol) N-Boc-piperidinemethanol in 115 ml THF -phosphine and cooled to 5 ° C. To the suspension kept at this temperature, 13.3 ml (67.8 mmol) of diisopropylazodicarboxylate are added dropwise with stirring within 45 minutes. The reaction mixture is stirred for 1 hour at room temperature. Then a further 22.2 g (84.7 mmol) triphenylphosphine and 16.6 ml (84.7 mmol)
Diisopropyl azodicarboxylate added. The reaction mixture turns 18
Stirred for hours at room temperature and concentrated in vacuo. The resulting solid is filtered off with suction, washed with diethyl ether and chromatographed on a silica gel column with dichloromethane / methanol as the mobile phase: 4- [2- (3-methoxycarbonyl-phenyl) -pyrimidin-5-yloxymethyl] -piperidine-1-carboxylic acid tert .-butyl ester as lemon yellow crystals; 166 ° C .; ESI 428.
40.2 To a suspension of 1.71 g (3.99 mmol) of 4- [2- (3-methoxycarbonyl-phenyl) -pyrimidin-5-yloxymethyl] -piperidine-1-carboxylic acid tert-butyl ester in 20 ml of THF are added under nitrogen 25 ml (25 mmol) of a 1 M solution of diisobutylaluminum hydride in THF were added dropwise. The reaction mixture is stirred at room temperature for 1 hour, and 1 ml of a saturated sodium sulfate solution is added. The resulting precipitate is filtered off with suction and washed with THF and hot 2-propanol. The filtrate is evaporated and recrystallized from tert-butyl methyl ether: {3- [5- (1-Methyl-piperidin-4-ylmethoxy) -pyrimidin-2-yl] -phenyl} -methanol as beige crystals; Mp 175 ° C; ESI 314.
40.3 To a solution of 313 mg (1.00 mmol) {3- [5- (1-methyl-piperidin-4-ylmethoxy) -pyrimidin-2-yl] -phenyl} -methanol in 2 ml THF are successively added 264 mg (1.30 mmol) 3- (6-oxo-1, 6-dihydro-pyridazin-3-yl) benzonitrile and 397 mg (1.5 mmol) triphenylphosphine are added. The reaction mixture is cooled in an ice bath and 294 μl (1.5 mmol) of diisopropylazodicarboxylate are added dropwise with stirring. The
The reaction mixture is stirred for 18 hours at room temperature and evaporated. The residue is chromatographed on a silica gel column using dichloromethane / methanol. The product-containing fractions are combined, evaporated, the residue digested with tert-butyl methyl ether, filtered off with suction and dried in vacuo: 3- (1- {3- [5- (1-methylpiperidin-4-ylmethoxy) pyrimidine) -2-yl] -benzyl} -6-oxo-1,6-dihydro-pyridazin-3-yl) -benzonitrile as colorless crystals; M.p. 177 ° C; ESI 493; 1 H-NMR (de-DMSO): δ [ppm] = 1.33 (m, 2H), 1.75 (m, 3H), 1.89 (m, 2H), 2.17 (S, 3H), 2.80 (m, 2H), 4.05 (d, J = 6.1 Hz 1 2H), 5.45 (s, 2H) 1 7.16 (d, J = 10 Hz, 1 H), 7.49 (m, 2H), 7.73 (t, J = 7.8 Hz, 1H ), 7.93 (d, J = 7.8 Hz, 1H) 1 8.17 (d, J = 10 Hz, 1H), 8.24 (m, 2H), 8.38 (m, 2H), 8.64 (s, 2H).
The hemisulfate, citrate, tartrate, sulfate, succinate and hydrochloride are obtained from “A257” by salt formation.
Scheme 1. Reagents and conditions: a) PdCl2(PPh3)2, Na2CO3, ethanol/toluene/water, 90 °C, 8 h; b) SOCl2, CHCl3, reflux; c) SeO2, dioxane:H2O = 10:1, reflux, 12 h; d) NaOH, −30 °C; e) NaH, DMF/THF, 0 °C—room temperature, 12 h; f) dry ethanol, reflux; g) NaOH, DMF/H2O, 60 °C, 8 h, N2.
Scheme 2. Reagents and conditions: a) N,N-diisopropylethylamine, dry CH2Cl2, 0 °C—room temperature, 6 h; b) PdCl2(PPh3)2, Na2CO3, ethanol/toluene/water, 90 °C, 8 h; c) 10% aq. HCl, MeOH, reflux; d) K2CO3, dry DMF, 80 °C, 12 h; e) NaOH, DMF/H2O, 60 °C, 8 h, N2; f) PPh3, DIAD, THF, 0 °C—room temperature; g) SOCl2, CHCl3, reflux; h) 35% formaldehyde, NaBH4, MeOH.
Scheme 3. Reagents and conditions: a) PdCl2(PPh3)2, Na2CO3, ethanol/toluene/water, 90 °C, 8 h; b) NaBH4, MeOH, 0 °C—room temperature, 1 h; c) SOCl2, CHCl3, reflux; d) K2CO3, dry DMF, 80 °C, 12 h; e) 31a–31b: NaOH, DMF/H2O, 60 °C, 8 h, N2; f) 31c–31g: NaH, dry DMF, 0 °C—room temperature, 5 h.
Scheme 4. Reagents and conditions: a) K2CO3, dry DMF, 80 °C, 12 h; b) PdCl2(PPh3)2, Na2CO3, DME/DMF/water, 89 °C, 12 h; c) NaOH, DMF/H2O, 60 °C, 8 h, N2.
Scheme 5. Reagents and conditions: a) K2CO3, dry DMF, 80 °C, 12 h; b) PdCl2(PPh3)2, Na2CO3, DME/DMF/water, 89 °C, 12 h; c) NaOH, DMF/H2O, 60 °C, 8 h, N2.
Tirabrutinib (Velexbru®) is an orally administered, small molecule, Bruton’s tyrosine kinase (BTK) inhibitor being developed by Ono Pharmaceutical and its licensee Gilead Sciences for the treatment of autoimmune disorders and haematological malignancies. Tirabrutinib irreversibly and covalently binds to BTK in B cells and inhibits aberrant B cell receptor signalling in B cell-related cancers and autoimmune diseases. In March 2020, oral tirabrutinib was approved in Japan for the treatment of recurrent or refractory primary central nervous system lymphoma. Tirabrutinib is also under regulatory review in Japan for the treatment of Waldenström’s macroglobulinemia and lymphoplasmacytic lymphoma. Clinical development is underway in the USA, Europe and Japan for autoimmune disorders, chronic lymphocytic leukaemia, B cell lymphoma, Sjogren’s syndrome, pemphigus and rheumatoid arthritis. This article summarizes the milestones in the development of tirabrutinib leading to the first approval of tirabrutinib for the treatment of recurrent or refractory primary central nervous system lymphoma in Japan.
ClassAntineoplastics; Ethers; Fluorobenzenes; Morpholines; Pyridines; Pyrimidinones; Pyrroles; Small molecules
Mechanism of Action Type 1 fibroblast growth factor receptor antagonists; Type 3 fibroblast growth factor receptor antagonists; Type 4 fibroblast growth factor receptor antagonists; Type-2 fibroblast growth factor receptor antagonists
Orphan Drug Status Yes – Myeloproliferative disorders; Lymphoma; Cholangiocarcinoma
MarketedCholangiocarcinoma
Phase IIBladder cancer; Lymphoma; Myeloproliferative disorders; Solid tumours; Urogenital cancer
Phase I/IICancer
05 Nov 2020Preregistration for Cholangiocarcinoma (Late-stage disease, Metastatic disease, First line therapy, Inoperable/Unresectable) in Japan (PO) in November 2020
05 Nov 2020Incyte Corporation stops enrolment in the FIGHT-205 trial for Bladder cancer due to regulatory feedback
26 Oct 2020Preregistration for Cholangiocarcinoma (Second-line therapy or greater, Inoperable/Unresectable, Late-stage disease, Metastatic disease) in Canada (PO)
Pemigatinib, also known as INCB054828, is an orally bioavailable inhibitor of the fibroblast growth factor receptor (FGFR) types 1, 2, and 3 (FGFR1/2/3), with potential antineoplastic activity. FGFR inhibitor INCB054828 binds to and inhibits FGFR1/2/3, which may result in the inhibition of FGFR1/2/3-related signal transduction pathways. This inhibits proliferation in FGFR1/2/3-overexpressing tumor cells.
Pemigatinib (INN),[2] sold under the brand name Pemazyre, is a medication for the treatment of adults with previously treated, unresectable locally advanced or metastatic bile duct cancer (cholangiocarcinoma) with a fibroblast growth factor receptor 2 (FGFR2) fusion or other rearrangement as detected by an FDA-approved test.[3][4] Pemigatinib works by blocking FGFR2 in tumor cells to prevent them from growing and spreading.[3]
Pemigatinib belongs to a group of medicines called protein kinase inhibitors.[5] It works by blocking enzymes known as protein kinases, particularly those that are part of receptors (targets) called fibroblast growth factor receptors (FGFRs).[5] FGFRs are found on the surface of cancer cells and are involved in the growth and spread of the cancer cells.[5] By blocking the tyrosine kinases in FGFRs, pemigatinib is expected to reduce the growth and spread of the cancer.[5]
The most common adverse reactions are hyperphosphatemia and hypophosphatemia (electrolyte disorders), alopecia (spot baldness), diarrhea, nail toxicity, fatigue, dysgeusia (taste distortion), nausea, constipation, stomatitis (sore or inflammation inside the mouth), dry eye, dry mouth, decreased appetite, vomiting, joint pain, abdominal pain, back pain and dry skin.[3][4] Ocular (eye) toxicity is also a risk of pemigatinib.[3][4]
Medical uses
Cholangiocarcinoma is a rare form of cancer that forms in bile ducts, which are slender tubes that carry the digestive fluid bile from the liver to gallbladder and small intestine.[3] Pemigatinib is indicated for the treatment of adults with bile duct cancer (cholangiocarcinoma) that is locally advanced (when cancer has grown outside the organ it started in, but has not yet spread to distant parts of the body) or metastatic (when cancer cells spread to other parts of the body) and who have tumors that have a fusion or other rearrangement of a gene called fibroblast growth factor receptor 2 (FGFR2).[3] It should be used in patients who have been previously treated with chemotherapy and whose cancer has a certain type of abnormality in the FGFR2 gene.[6]
History
Pemigatinib was approved for use in the United States in April 2020 along with the FoundationOne CDX (Foundation Medicine, Inc.) as a companion diagnostic for patient selection.[3][4][7]
The approval of pemigatinib in the United States was based on the results the FIGHT-202 (NCT02924376) multicenter open-label single-arm trial that enrolled 107 participants with locally advanced or metastatic cholangiocarcinoma with an FGFR2 fusion or rearrangement who had received prior treatment.[3][4][6] The trial was conducted at 67 sites in the United States, Europe, and Asia.[6] During the clinical trial, participants received pemigatinib once a day for 14 consecutive days, followed by 7 days off, in 21-day cycles until the disease progressed or the patient experienced an unreasonable level of side effects.[3][4][6] To assess how well pemigatinib was working during the trial, participants were scanned every eight weeks.[3] The trial used established criteria to measure how many participants experienced a complete or partial shrinkage of their tumors during treatment (overall response rate).[3] The overall response rate was 36% (95% CI: 27%, 45%), with 2.8% of participants having a complete response and 33% having a partial response.[3] Among the 38 participants who had a response, 24 participants (63%) had a response lasting six months or longer and seven participants (18%) had a response lasting 12 months or longer.[3][4]
On 24 August 2018, orphan designation (EU/3/18/2066) was granted by the European Commission to Incyte Biosciences Distribution B.V., the Netherlands, for pemigatinib for the treatment of biliary tract cancer.[5] On 17 October 2019, orphan designation EU/3/19/2216 was granted by the European Commission to Incyte Biosciences Distribution B.V., the Netherlands, for pemigatinib for the treatment of myeloid/lymphoid neoplasms with eosinophilia and rearrangement of PDGFRA, PDGFRB, or FGFR1, or with PCM1-JAK2.[10]
PATENT
US 20200281907
The present disclosure is directed to, inter alia, methods of treating cancer in a patient in need thereof, comprising administering pemigatinib, which is 3-(2,6-difluoro-3,5-dimethoxyphenyl)-1-ethyl-8-(morpholin-4-ylmethyl)-1,3,4,7-tetrahydro-2H-pyrrolo[3′,2′: 5,6]pyrido[4,3-d]pyrimidin-2-one, having the structure shown below:
Pemigatinib is described in U.S. Pat. No. 9,611,267, the entirety of which is incorporated herein by reference. Pemigatinib is further described in US Publication Nos.: 2019/0337948 and 2020/0002338, the entireties of which are incorporated herein by reference.
Provided herein is a method of treating cancer comprising administering a therapy to a patient in need thereof, wherein the therapy comprises administering a therapeutically effective amount of pemigatinib to the patient while avoiding the concomitant administration of a CYP3A4 perpetrator.
A mixture of 4-chloro-1H-pyrrolo[2,3-b]pyridine-5-carbaldehyde (CAS #958230-19-8, Lakestar Tech, Lot: 124-132-29: 3.0 g, 17 mmol) and ethylamine (10M in water, 8.3 mL, 83 mmol) in 2-methoxyethanol (20 mL, 200 mmol) was heated to 130° C. and stirred overnight. The mixture was cooled to room temperature then concentrated under reduced pressure. The residue was treated with 1N HCl (30 mL) and stirred at room temperature for 1 h then neutralized with saturated NaHCO 3 aqueous solution. The precipitate was collected via filtration then washed with water and dried to provide the desired product (2.9 g, 92%). LC-MS calculated for C 10H 12N 3O [M+H] + m/z: 190.1; found: 190.1.
A mixture of 4-(ethylamino)-1H-pyrrolo[2,3-b]pyridine-5-carbaldehyde (7.0 g, 37 mmol), 2,6-difluoro-3,5-dimethoxyaniline (9.1 g, 48 mmol) and [(1S)-7,7-dimethyl-2-oxobicyclo[2.2.1]hept-1-yl]methanesulfonic acid (Aldrich, cat #21360: 2 g, 7 mmol) in xylenes (250 mL) was heated to reflux with azeotropic removal of water using Dean-Stark for 2 days at which time LC-MS showed the reaction was complete. The mixture was cooled to room temperature and the solvent was removed under reduced pressure. The residue was dissolved in tetrahydrofuran (500 mL) and then 2.0 M lithium tetrahydroaluminate in THF (37 mL, 74 mmol) was added slowly and the resulting mixture was stirred at 50° C. for 3 h then cooled to room temperature. The reaction was quenched by addition of water, 15% aqueous NaOH and water. The mixture was filtered and washed with THF. The filtrate was concentrated and the residue was washed with CH 2Cl 2 and then filtered to get the pure product (11 g, 82%). LC-MS calculated for C 18H 21F 2N 4O 2[M+H] + m/z: 363.2; found: 363.1.
A solution of triphosgene (5.5 g, 18 mmol) in tetrahydrofuran (30 mL) was added slowly to a mixture of 5-{[(2,6-difluoro-3,5-dimethoxyphenyl)amino]methyl}-N-ethyl-1H-pyrrolo[2,3-b]pyridin-4-amine (5.6 g, 15 mmol) in tetrahydrofuran (100 mL) at 0° C. and then the mixture was stirred at room temperature for 6 h. The mixture was cooled to 0° C. and then 1.0 M sodium hydroxide in water (100 mL, 100 mmol) was added slowly. The reaction mixture was stirred at room temperature overnight and the formed precipitate was collected via filtration, washed with water, and then dried to provide the first batch of the purified desired product. The organic layer in the filtrate was separated and the aqueous layer was extracted with methylene chloride. The combined organic layer was concentrated and the residue was triturated with methylene chloride then filtered and dried to provide another batch of the product (total 5.5 g, 92%). LC-MS calculated for C 19H 19F 2N 4O 3[M+H] + m/z: 389.1; found: 389.1.
To a solution of 3-(2,6-difluoro-3,5-dimethoxyphenyl)-1-ethyl-1,3,4,7-tetrahydro-2H-pyrrolo[3′,2′:5,6]pyrido[4,3-d]pyrimidin-2-one (900 mg, 2.32 mmol) in N,N-dimethylformamide (20 mL) cooled to 0° C. was added sodium hydride (185 mg, 4.63 mmol, 60 wt % in mineral oil). The resulting mixture was stirred at 0° C. for 30 min then benzenesulfonyl chloride (0.444 mL, 3.48 mmol) was added. The reaction mixture was stirred at 0° C. for 1.5 h at which time LC-MS showed the reaction completed to the desired product. The reaction was quenched with saturated NH 4Cl solution and diluted with water. The white precipitate was collected via filtration then washed with water and hexanes, dried to afford the desired product (1.2 g, 98%) as a white solid which was used in the next step without further purification. LC-MS calculated for C 25H 23F 2N 4O 5S [M+H] + m/z: 529.1; found: 529.1.
To a solution of 3-(2,6-difluoro-3,5-dimethoxyphenyl)-1-ethyl-7-(phenylsulfonyl)-1,3,4,7-tetrahydro2H-pyrrolo[3′,2′: 5,6]pyrido[4,3-d]pyrimidin-2-one (1.75 g, 3.31 mmol) in tetrahydrofuran (80 mL) at −78° C. was added freshly prepared lithium diisopropylamide (1M in tetrahydrofuran (THF), 3.48 mL, 3.48 mmol). The resulting mixture was stirred at −78° C. for 30 min then N,N-dimethylformamide (1.4 mL, 18 mmol) was added slowly. The reaction mixture was stirred at −78° C. for 30 min then quenched with water and extracted with EtOAc. The organic extracts were combined then washed with water and brine. The organic layer was dried over Na 2SO 4 and concentrated. The residue was purified by flash chromatography eluted with 0 to 20% EtOAc in DCM to give the desired product as a white solid (1.68 g, 91%). LC-MS calculated for C 26H 23F 2N 4O 6S (M+H) + m/z: 557.1; found: 556.9.
To a solution 3-(2,6-difluoro-3,5-dimethoxyphenyl)-1-ethyl-2-oxo-7-(phenylsulfonyl)-2,3,4,7-tetrahydro-1H-pyrrolo[3′,2′: 5,6]pyrido[4,3-d]pyrimidine-8-carbaldehyde (1.73 g, 3.11 mmol) in dichloromethane (50 mL) was added morpholine (0.95 mL, 11 mmol), followed by acetic acid (2 mL, 30 mmol). The resulting yellow solution was stirred at room temperature overnight then sodium triacetoxyborohydride (2.3 g, 11 mmol) was added. The mixture was stirred at room temperature for 3 h at which time LC-MS showed the reaction went to completion to the desired product. The reaction was quenched with saturated NaHCO 3 then extracted with ethyl acetate (EtOAc). The organic extracts were combined then washed with water and brine. The organic layer was dried over Na 2SO 4 and concentrated. The residue was purified by flash chromatography eluted with 0 to 40% EtOAc in DCM to give the desired product as a yellow solid (1.85 g, 95%). LC-MS calculated for C 30H 32F 2N 5O 6S (M+H) + m/z: 628.2; found: 628.0.
To a solution of 3-(2,6-difluoro-3,5-dimethoxyphenyl)-1-ethyl-8-(morpholin-4-ylmethyl)-7-(phenylsulfonyl)-1,3,4,7-tetrahydro-2H-pyrrolo[3′,2′: 5,6]pyrido[4,3-d]pyrimidin-2-one (1.5 g, 2.4 mmol) in tetrahydrofuran (40 mL) was added tetra-n-butylammonium fluoride (1M in THF, 7.2 mL, 7.2 mmol). The resulting solution was stirred at 50° C. for 1.5 h then cooled to room temperature and quenched with water. The mixture was extracted with dichloromethane (DCM) and the organic extracts were combined then washed with water and brine. The organic layer was dried over Na 2SO 4 and concentrated. The residue was purified by flash chromatography eluted with 0 to 10% MeOH in DCM to give the desired product as a white solid, which was further purified by prep HPLC (pH=2, acetonitrile/H 2O). LC-MS calculated for C 24H 28F 2N 5O 4 (M+H) + m/z: 488.2; found: 488.0. 1H NMR (500 MHz, DMSO) δ 12.09 (s, 1H), 8.06 (s, 1H), 7.05 (t, J=8.1 Hz, 1H), 6.87 (s, 1H), 4.78 (s, 2H), 4.50 (s, 2H), 4.17 (q, J=6.8 Hz, 2H), 3.97 (br, 2H), 3.89 (s, 6H), 3.65 (br, 2H), 3.37 (br, 2H), 3.15 (br, 2H), 1.37 (t, J=6.8 Hz, 3H).
The present disclosure is directed to, inter alia, solid forms, including crystalline forms and amorphous forms, of 3-(2,6-difluoro-3,5-dimethoxyphenyl)-l-ethyl-8-(morpholin-4-ylmethyl)- 1 ,3,4,7 -tetrahydro-2H-pyrrolo [3 ‘,2’ : 5 ,6]pyrido [4,3 -d]pyrimidin-2-one
(Compound 1), and processes and intermediates for preparing the compound. The structure of Compound 1 is shown below.
Compound 1
Compound 1 is described in US Patent No. 9,611,267, the entirety of which is incorporated herein by reference.
Example 1
Synthesis of 3-(2,6-difluoro-3,5-dimethoxyphenyl)-l-ethyl-8-(morpholin-4-ylmethyl)-l^, 4,7-tetrahydro-2H-pyrrolo[3f,2f:5,6]pyrido[4r3-d]pyrimidin-2-one (Compound 1) Scheme 1.
To a l-L flask was added 4-chloro-5-(l,3-dioxolan-2-yl)-l-(phenylsulfonyl)-lH-pyrrolo [2,3-b] pyridine (50.0 g, 137 mmol) (see, e.g., Example 2) and tetrahydrofuran (THF, 266 g, 300 mL) under N2. To this mixture at -70 °C was added 2.0 M lithium
diisopropylamide in THF/heptane/ethyl benzene (77.4 g, 95 mL, 190 mmol, 1.4 eq.). The mixture was stirred at -70 °C for 1 h. To the mixture was added /V- formyl morpholine (29.7 g, 258 mmol, 1.9 eq.) in THF (22. 2 g, 25 mL) dropwise. The reaction was done in 30 min after addition. LC/MS showed that the desired product, 4-chloro-5-(l, 3-dioxolan-2-yl)-l-(phenylsulfonyl)- 1 //-pyrrolo [2, 3-61 pyridine-2-carbaldehyde, was formed cleanly. The reaction was quenched with acetic acid (16.4 g, 15.6 mL, 274 mmol, 2.0 eq.) and the dry ice cooling was removed. To the mixture was added morpholine (33.7 g, 33.5 mL, 387 mmol, 2.83 eq.) followed by acetic acid (74.0 g, 70 mL, 1231 mmol, and 9.0 eq.) at 0 °C (internal temperature rose from 0 °C to 18 °C) and stirred overnight. Sodium triacetoxyborohydride (52.50 g, 247.7 mmol, 1.8 eq.) was added and the reaction mixture temperature rose from 20 °C to 32 °C. The mixture was stirred at room temperature for 30 min. HPLC & LC/MS indicated the reaction was complete. Water (100 g, 100 mL) was added followed by 2.0 M sodium carbonate (Na2C03) in water (236 g, 200 mL, 400 mmol, 2.9 eq.) slowly (off gas!). The mixture was stirred for about 30 min. The organic layer was separated and water (250 g, 250 mL) and heptane (308 g, 450 mL) were added. The resulting slurry was stirred for 1 h and the solid was collected by filtration. The wet cake was washed with heptane twice (75.00 mL x 2, 51.3 g x 2) before being dried in oven at 50 °C overnight to give the desired product, 4-((4-chloro-5-( 1 3-dioxolan-2-yl)- 1 -(phenylsulfonyl)- 1 //-pyrrolo|2.3-6 |pyridin-2-yl)methyl)morpholine as a light brown solid (52.00 g, 81.8 % yield): LCMS calculated for C21H23CIN2O5S [M+H]+: 464.00; Found: 464.0; ftf NMR ^OO MHz, DMSO-de) d 8.48 (s, 1 H), 8.38 (m, 2H), 7.72 (m, 1H), 7.64 (m, 2H), 6.83 (s, 1H), 6.13 (s, 1H), 4.12 (m, 2H), 4.00 (m, 2H), 3.92 (s, 2H), 3.55 (m, 4H), 2.47 (m, 4H).
Step 2: Synthesis of 4-chloro-2-(morpholinomethyl)-l-(phenylsulfonyl)-lH-pyrrolo[2, 3-b] pyridine-5 -carbaldehyde
To a 2 L reactor with a thermocouple, an addition funnel, and a mechanical stirrer was charged 4-((4-chloro-5 -(1 ,3 -dioxolan-2-yl)- 1 -(phenylsulfonyl)- 1 //-pyrrolo [2,3 -6]pyridin-2-yl)methyl)morpholine (20.00 g, 43.1 mmol) and dichloromethane (265 g, 200 mL) at room temperature. The resulting mixture was stirred at room temperature (internal temperature
was 19.5 °C) to achieve a solution. To the resulting solution was added an aqueous hydrochloric acid solution (0.5 M, 240 g, 200.0 ml, 100 mmol, 2.32 eq.) at room temperature in 7 min. After over 23 h agitations at room temperature, the bilayer reaction mixture turned into a thick colorless suspension. When HPLC showed the reaction was complete, the slurry was cooled to 0-5 °C and aqueous sodium hydroxide solution (1 N, 104 g, 100 mL, 100 mmol, and 2.32 eq.) was added in about 10 min to adjust the pH of the reaction mixture to 10-11. «-Heptane (164 g, 240 mL) was added and the reaction mixture and the mixture were stirred at room temperature for 1 h. The solid was collected by filtration and the wet cake was washed with water (2 x 40 mL), heptane (2 x 40 ml) before being dried in oven at 50 °C under vacuum to afford the desired product, 4-chloro-2-(morpholinomethyl)-l-(phenylsulfonyl)- 1 //-pyrrolo|2.3-/i |pyridine-5-carbaldehyde as a light brown solid (16.9 g, 93% yield): LCMS calculated for C19H19CIN3O4S [M+H]+: 420.00; Found: 420.0; ¾ NMR (400 MHz, DMSO-de) d 10.33 (s, 1H), 8.76 (s, 1 H), 8.42 (m, 2H), 7.74 (m, 1H), 7.65 (m, 2H), 6.98 (s, 1H), 3.96 (m, 2H), 3.564 (m, 4H), 2.51 (m, 4H).
To a 2-L reactor equipped with a thermocouple, a nitrogen inlet and mechanical stirrer were charged AOV-dimethyl formamide (450 mL, 425 g), 4-chloro-2-(morpholinomethyl)-l-(phenylsulfonyl)- 1 //-pyrrolo|2.3-6 |pyridine-5-carbaldehyde (30.0 g, 71.45 mmol) and 2,6-difluoro-3,5-dimethoxyanihne (14.2 g, 75.0 mmol). To this suspension (internal temperature 20 °C) was added chlorotrimethylsilane (19.4 g, 22. 7 mL, 179 mmol) dropwise in 10 min at room temperature (internal temperature 20-23 °C). The suspension changed into a solution in 5 min after the chlorotrimethylsilane addition. The solution was stirred at room temperature for 1.5 h before cooled to 0-5 °C with ice-bath. Borane-THF complex in THF (1.0 M, 71.4 mL, 71.4 mmol, 64.2 g, 1.0 eq.) was added dropwise via additional funnel over 30 min while maintaining temperature at 0-5 °C. After addition, the mixture was stirred for 4 h. Water (150 g, 150 mL) was added under ice-bath cooling in 20 min, followed by slow addition of ammonium hydroxide solution (28% N¾, 15.3 g, 17 ml, 252 mmol, 3.53 eq.) to pH 9-10 while maintaining the temperature below 10 °C. More water (250 mL, 250 g) was added through the additional funnel. The slurry was stirred for 30 min and the solids were collected by filtration. The wet cake was washed with water (90 g x 2, 90 ml x 2) and heptane (61.6 g x2, 90 ml x 2). The product w as suction dried overnight to give the desired product LG-((4-chloro-2-(morphohnomethyl)-l-(phenylsulfonyl)-li/-pyrrolo[2,3-Z>]pyridin-5-yl)methyl)-2,6- difluoro-3,5-dimethoxyaniline (41.6 g, 96% yield): LCMS calculated for C27H28ClF2N405S[M+H]+: 593.10; Found: 593.1 ; ¾ NMR (400 MHz, DMSO-d6) 5 8.36 (m, 2H), 8.28 (s, 1H), 7.72 (m, 1H), 7.63 (m, 2H), 6.78 (s, 1H), 6.29 (m, 1H), 5.82 (m, 1H), 4.58 (m, 2H), 3.91 (s, 2H), 3.76 (s, 6H), 3.56 (m, 4H), 2.47 (m, 4H).
To a 2-L, 3-neck round bottom flask fitted with a thermocouple, a nitrogen bubbler inlet, and a magnetic stir were charged /V-((4-chloro-2-(morpholinomethyl)-l-(phenylsulfonyl)-li/-pyrrolo[2,3-b]pyridin-5-yl)methyl)-2,6-difluoro-3,5-dimethoxyaniline (67.0 g, 113 mmol) and acetonitrile (670 ml, 527 g). The suspension was cooled to 0-5 °C.
To the mixture was charged ethyl isocyanate (17.7 mL, 15.9 g, 224 mmol, 1.98 eq.) over 30 sec. The temperature stayed unchanged at 0.7 °C after the charge. Methanesulfonic acid (16.1 mL, 23.9 g, 248 mmol, 2.2 eq.) was charged dropwise over 35 min while maintaining the temperature below 2 °C. The mixture was warmed to room temperature and stirred overnight. At 24 h after addition showed that the product was 93.7%, unreacted SM was 0.73% and the major impurity (bis-isocyanate adduct) was 1.3%. The mixture was cooled with an ice-bath and quenched with sodium hydroxide (NaOH) solution (1.0M, 235 mL, 244 g, 235 mmol, 2.08 eq.) over 20 min and then saturated aqueous sodium bicarbonate
(NaHCCh) solution (1.07 M, 85 mL, 91 g, 0.091 mol, 0.80 eq.) over 10 min. Water (550 mL, 550 g) was added and the liquid became one phase. The mixture was stirred for 2 h and the solids were collected by filtration, washed with water (165 mL, 165 g) to give l-((4-chloro-2-(morpholinomethyl)- 1 -(phenylsulfonyl)- 1 //-pyrrolo| 2.3-6 |p\ ri din-5 -y l (methy l )- 1 -(2,6-difluoro-3,5-dimethoxyphenyl)-3-ethylurea ( 70.3 g, 93.7% yield).
The crude l-((4-chloro-2-(morpholinomethyl)-l -(phenylsulfonyl)- li/-pyrrolo [2, 3-61 pyridin-5-yl) methyl)- 1 -(2, 6-difluoro-3, 5-dimethoxyphenyl)-3-ethylurea (68.5 g, 103 mmol) was added in to acetonitrile (616 mL, 485 g). The mixture was heated 60-65 °C and an amber colored thin suspension was obtained. The solid was filtered off with celite and the celite was washed with acetonitrile (68.5 mL, 53.8 g). To the pale yellow filtrate was added water (685 g, 685 ml) to form a slurry. The slurry was stirred overnight at room temperature and filtered. The solid was added to water (685 mL, 685 g) and stirred at 60 °C for 2 h. The solid was filtered and re-slurred in heptane (685 mL, 469 g) overnight. The product was dried in an oven at 50 °C under vacuum for 48 h to afford l-((4-chloro-2-(morpholinomethyl)-l-(phenylsulfonyl)- 1 //-pyrrolo|2.3-6 |pyridin-5-yl)methyl)- 1 -(2.6-difluoro-3.5-
dimethoxyphenyl)-3-ethylurea as a colorless solid (62.2 g, 90.8% yield, 99.9% purity by HPLC area%). KF was 0.028%. Acetonitrile (by ‘H NMR) was about 1.56%, DCM (by ‘H NMR) 2.0%: LCMS calculated for C30H33CIF2N5O6S [M+H]+: EM: 664.17; Found: 664.2; ¾ NMR (400 MHz, DMSO-de) d 8.33 (m, 2H), 8.31 (s, 1H), 7.72 (m, 1H), 7.64 (m, 1H), 6.96 (m, 2H), 6.73 (s, 1H), 6.43 (m, 1H), 4.87 (s, 2H), 3.90 (s, 2H), 3.77 (s, 6H), 3.54 (m, 4H),
To a 2000 mL flask equipped with a thermal couple, a nitrogen inlet, and a mechanical stirrer were charged dry l-((4-chloro-2-(morpholinomethyl)-l-(phenylsulfonyl)-1 //-pyrrolo| 2.3-6 |pyridin-5-yl)methyl)- 1 -(2.6-dinuoro-3.5-dimetho\yphenyl)-3-ethylurea (30.0 g, 45.2 mmol, KF=0. l l%) and tetrahydrofuran (1200 mL, 1063 g). To this suspension at room temperature was charged 1.0 M lithium hexamethyldisilazide in THF (62.3 mL, 55.5 g, 62.3 mmol, 1.38 eq). The mixture turned into a solution after the base addition. The reaction mixture was stirred for 2 h and HPLC shows the starting material was not detectable. To this mixture was added 1.0 M hydrochloric acid (18.1 mL, -18.1 g. 18.1 mmol, 0.4 eq.). The solution was concentrated to 600 mL and water (1200 mL, 1200 g) was added. Slurry was formed after water addition. The slurry was stirred for 30 min at room temperature and the solid was collected by filtration. The wet cake was washed with water twice (60 mLx2,
60 gx2) and dried at 50 °C overnight to give 3-(2,6-difluoro-3,5-dimethoxyphenyl)-l-ethyl-8-(morpholin-4-ylmethyl)-7-(phenylsulfonyl)-l,3,4,7-tetrahydro-2H-pyrrolo[3′,2′:5,6]pyrido[4, 3-d]pyrimidin-2-one as a light brown solid (26.58 g, as-is yield 93.7%): THF by ‘H NMR 0.32%, KF 5.26%, adjusted yield was 88.5%: LCMS calculated for C30H32F2N5O6S [M+H]+: EM: 628.20; Found: 628.2; ¾ NMR (400 MHz, DMSO-de) d 8.41 (m, 2H), 8.07 (s, 1H), 7.70 (m, 1H), 7.63 (m, 2H), 7.05 (m, 1H), 6.89 (s, 1H), 4.76 (s, 2H), 4.09 (m, 2H), 3.93 (s, 2H), 3.89 (s, 6H), 3.60 (m, 4H), 2.50 (m, 4H), 1.28 (m, 3H).
To a stirring suspension of 3-(2,6-difluoro-3,5-dimethoxyphenyl)-l-ethyl-8-(morpholinomethyl)-7-(phenylsulfonyl)-l,3,4,7-tetrahydro-2i/-pyrrolo[3′,2′:5,6]pyrido[4,3-d]pyrimidin-2-one (10.0 g, 15.93 mmol) in l,4-dioxane (100 ml, 103 g) in a 500 mL flask equipped with a nitrogen inlet, a condenser, a thermocouple and a heating mantle was added 1 M aqueous sodium hydroxide (63.7 ml, 66.3 g, 63.7 mmol). The reaction mixture was heated at 75 °C for 18 h. LCMS showed the reaction was complete. Water (100 mL, 100 g) was added to give a thick suspension. This slurry was stirred at room temperature for 1 h and filtered. The cake was washed with water (3 x 10 mL, 3 x 10 g) and heptane (2 x 10 mL, 2 x 6.84 g). The cake was dried overnight by pulling a vacuum through the filter cake and then dried in an oven at 50 °C under vacuum overnight to give 3-(2,6-difluoro-3,5-dimethoxyphenyl)-l-ethyl-8-(morpholin-4-ylmethyl)-l,3,4,7-tetrahydro-2H-pyrrolo[3′,2′:5, 6]pyrido[4,3-d]pyrimidin-2-one (6.8 g, 87.6% yield): LCMS calculated for C24H28F2N5O4 [M+H]+: 488.20; Found: 488.2.
[0833] To a solution of 3-(2,6-difluoro-3,5-dimethoxyphenyl)-1-ethyl-1,3,4,7-tetrahydro-2H-pyrrolo[3′,2′:5,6]pyrido[4,3-d]pyrimidin-2-one (Example 49, Step 3: 900 mg, 2.32 mmol) in N,N-dimethylformamide (20 mL) cooled to 0° C. was added sodium hydride (185 mg, 4.63 mmol, 60 wt % in mineral oil). The resulting mixture was stirred at 0° C. for 30 min then benzenesulfonyl chloride (0.444 mL, 3.48 mmol) was added. The reaction mixture was stirred at 0° C. for 1.5 h at which time LC-MS showed the reaction completed to the desired product. The reaction was quenched with saturated NH4Cl solution and diluted with water. The white precipitate was collected via filtration then washed with water and hexanes, dried to afford the desired product (1.2 g, 98%) as a white solid which was used in the next step without further purification. LC-MS calculated for C25H23F2N4O5S [M+H]+ m/z: 529.1; found: 529.1.
[0835] To a solution of 3-(2,6-difluoro-3,5-dimethoxyphenyl)-1-ethyl-7-(phenylsulfonyl)-1,3,4,7-tetrahydro-2H-pyrrolo[3′,2′:5,6]pyrido[4,3-d]pyrimidin-2-one (1.75 g, 3.31 mmol) in tetrahydrofuran (80 mL) at −78° C. was added freshly prepared lithium diisopropylamide (1M in tetrahydrofuran (THF), 3.48 mL, 3.48 mmol). The resulting mixture was stirred at −78° C. for 30 min then N,N-dimethylformamide (1.4 mL, 18 mmol) was added slowly. The reaction mixture was stirred at −78° C. for 30 min then quenched with water and extracted with EtOAc. The organic extracts were combined then washed with water and brine. The organic layer was dried over Na2SO4 and concentrated. The residue was purified by flash chromatography eluted with 0 to 20% EtOAc in DCM to give the desired product as a white solid (1.68 g, 91%). LC-MS calculated for C26H23F2N4O6S (M+H)+ m/z: 557.1; found: 556.9.
[0837] To a solution 3-(2,6-difluoro-3,5-dimethoxyphenyl)-1-ethyl-2-oxo-7-(phenylsulfonyl)-2,3,4,7-tetrahydro-1H-pyrrolo[3′,2′:5,6]pyrido[4,3-d]pyrimidine-8-carbaldehyde (1.73 g, 3.11 mmol) in dichloromethane (50 mL) was added morpholine (0.95 mL, 11 mmol), followed by acetic acid (2 mL, 30 mmol). The resulting yellow solution was stirred at room temperature overnight then sodium triacetoxyborohydride (2.3 g, 11 mmol) was added. The mixture was stirred at room temperature for 3 h at which time LC-MS showed the reaction went to completion to the desired product. The reaction was quenched with saturated NaHCO3 then extracted with ethyl acetate (EtOAc). The organic extracts were combined then washed with water and brine. The organic layer was dried over Na2SO4 and concentrated. The residue was purified by flash chromatography eluted with 0 to 40% EtOAc in DCM to give the desired product as a yellow solid (1.85 g, 95%). LC-MS calculated for C30H32F2N5O6S (M+H)+ m/z: 628.2; found: 628.0.
[0838] To a solution of 3-(2,6-difluoro-3,5-dimethoxyphenyl)-1-ethyl-8-(morpholin-4-ylmethyl)-7-(phenylsulfonyl)-1,3,4,7-tetrahydro-2H-pyrrolo[3′,2′:5,6]pyrido[4,3-d]pyrimidin-2-one (1.5 g, 2.4 mmol) in tetrahydrofuran (40 mL) was added tetra-n-butylammonium fluoride (1M in THF, 7.2 mL, 7.2 mmol). The resulting solution was stirred at 50° C. for 1.5 h then cooled to room temperature and quenched with water. The mixture was extracted with dichloromethane (DCM) and the organic extracts were combined then washed with water and brine. The organic layer was dried over Na2SO4 and concentrated. The residue was purified by flash chromatography eluted with 0 to 10% MeOH in DCM to give the desired product as a white solid, which was further purified by prep HPLC (pH=2, acetonitrile/H2O). LC-MS calculated for C24H28F2N5O4 (M+H)+ m/z: 488.2; found: 488.0. 1H NMR (500 MHz, DMSO) δ 12.09 (s, 1H), 8.06 (s, 1H), 7.05 (t, J=8.1 Hz, 1H), 6.87 (s, 1H), 4.78 (s, 2H), 4.50 (s, 2H), 4.17 (q, J=6.8 Hz, 2H), 3.97 (br, 2H), 3.89 (s, 6H), 3.65 (br, 2H), 3.37 (br, 2H), 3.15 (br, 2H), 1.37 (t, J=6.8 Hz, 3H).
^ World Health Organization (2018). “International nonproprietary names for pharmaceutical substances (INN): recommended INN: list 80”. WHO Drug Information. 32 (3): 479. hdl:10665/330907.
Clinical trial number NCT02924376 for “Efficacy and Safety of Pemigatinib in Subjects With Advanced/Metastatic or Surgically Unresectable Cholangiocarcinoma Who Failed Previous Therapy – (FIGHT-202)” at ClinicalTrials.gov
Ripretinib, sold under the brand name Qinlock, is a medication for the treatment of adults with advanced gastrointestinal stromal tumor (GIST), a type of tumor that originates in the gastrointestinal tract.[3] It is taken by mouth.[3] Ripretinib is a kinase inhibitor, meaning it works by blocking a type of enzyme called a kinase, which helps keep the cancer cells from growing.[3]
The most common side effects include alopecia (hair loss), fatigue, nausea, abdominal pain, constipation, myalgia (muscle pain), diarrhea, decreased appetite, palmar-plantar erythrodysesthesia syndrome (a skin reaction in the palms and soles) and vomiting.[3][4] Alopecia is a unique side effect to ripretinib, which is not seen with other tyrosine kinase inhibitors used to treat GISTs.
Ripretinib was approved for medical use in the United States in May 2020,[3] and in Australia in July 2020.[1] Ripretinib is the first new drug specifically approved in the United States as a fourth-line treatment for advanced gastrointestinal stromal tumor (GIST).
Medical uses
Ripretinib is indicated for the treatment of adults with advanced gastrointestinal stromal tumor (GIST), a type of tumor that originates in the gastrointestinal tract, who have received prior treatment with three or more kinase inhibitor therapies, including imatinib.[3] GIST is type of stomach, bowel, or esophagus tumor.[4]
Adverse effects
The most common side effects include alopecia (hair loss), fatigue, nausea, abdominal pain, constipation, myalgia (muscle pain), diarrhea, decreased appetite, palmar-plantar erythrodysesthesia syndrome (a skin reaction in the palms and soles) and vomiting.[3][4]
Ripretinib can also cause serious side effects including skin cancer, hypertension (high blood pressure) and cardiac dysfunction manifested as ejection fraction decrease (when the muscle of the left ventricle of the heart is not pumping as well as normal).[3][4]
Ripretinib may cause harm to a developing fetus or a newborn baby.[3][4]
History
Ripretinib was approved for medical use in the United States in May 2020.[3][5][6][4]
The approval of ripretinib was based on the results of an international, multi-center, randomized, double-blind, placebo-controlled clinical trial (INVICTUS/NCT03353753) that enrolled 129 participants with advanced gastrointestinal stromal tumor (GIST) who had received prior treatment with imatinib, sunitinib, and regorafenib.[3][7] The trial compared participants who were randomized to receive ripretinib to participants who were randomized to receive placebo, to determine whether progression free survival (PFS) – the time from initial treatment in the clinical trial to growth of the cancer or death – was longer in the ripretinib group compared to the placebo group.[3] During treatment in the trial, participants received ripretinib 150 mg or placebo once a day in 28-day cycles, repeated until tumor growth was found (disease progression), or the participant experienced intolerable side effects.[3][7] After disease progression, participants who were randomized to placebo were given the option of switching to ripretinib.[3][7] The trial was conducted at 29 sites in the United States, Australia, Belgium, Canada, France, Germany, Italy, the Netherlands, Poland, Singapore, Spain, and the United Kingdom.[4]
The major efficacy outcome measure was progression-free survival (PFS) based on assessment by blinded independent central review (BICR) using modified RECIST 1.1 in which lymph nodes and bone lesions were not target lesions and a progressively growing new tumor nodule within a pre-existing tumor mass must meet specific criteria to be considered unequivocal evidence of progression.[7] Additional efficacy outcome measures included overall response rate (ORR) by BICR and overall survival (OS).[7] The trial demonstrated a statistically significant improvement in PFS for participants in the ripretinib arm compared with those in the placebo arm (HR 0.15; 95% CI: 0.09, 0.25; p<0.0001).[7]
The FDA collaborated with the Australian Therapeutic Goods Administration (TGA) and Health Canada on the review of the application as part of Project Orbis.[3][7] The FDA approved ripretinib three months ahead of schedule.[3][7] As of May 2020, the review of the applications was ongoing for the Australian TGA and for Health Canada.[3][7]
[0125] Example A13: A mixture of Example C5 (2.191 g, 7.94 mmol), Example Bl (1.538 g, 8.33 mmol) and KF on alumina (40 wt%) (9.22 g, 63.5 mmol) in DMA (40 mL) was sonicated for 2 h. The mixture was filtered through a shallow bed of silica gel and rinsed well with EtOAc. The filtrate was washed with satd. NaHC03 (lx), 5% LiCl (2x), then brine (lx), dried (MgS04), and concentrated to dryness to afford 3-(5-amino-2-bromo-4-fluorophenyl)-7-chloro-l -ethyl- l,6-naphthyridin-2(lH)-one (2.793 g, 89% yield) as a brown solid. 1H NMR (400 MHz, DMSO-<¾): δ 8.77 (s, 1 H), 8.00 (s, 1 H), 7.74 (s, 1 H), 7.37 (d, 1 H), 6.77 (d, 1 H), 5.45 (s, 2 H), 4.27 (q, 2 H), 1.20 (t, 3 H); MS (ESI) m z: 398.0 [M+H]+.
[0126] Example A14: A suspension of Example A13 (1.50 g, 3.78 mmol) in dioxane (15 mL) was treated with methylamine (40% in water) (26.4 mL, 303 mmol) in a pressure tube and heated to 100°C overnight. The mixture was cooled to RT, treated with a large amount of brine, then diluted with EtOAc until all of the solids dissolved. The layers were separated, the aqueous layer extracted with additional EtOAc (lx) and the combined organics were washed with satd. NaHC03 (lx), dried (MgS04) and concentrated to dryness. The resulting solid was suspended in MeCN/H20, frozen and lyophilized to afford 3-(5-amino-2-bromo-4-fluorophenyl)-l-ethyl-7-(methylamino)-l,6-naphthyridin-2(lH)-one (1.32g, 89% yield) as a light brown solid. 1H NMR (400 MHz, DMSO-<¾): δ 8.37 (s, 1 H), 7.62 (s, 1 H), 7.30 (d, 1 H), 6.99 (q, 1 H), 6.73 (d, 1 H), 6.21 (s, 1 H), 5.33 (s, 2 H), 4.11 (q, 2 H), 2.84 (d, 3 H), 1.19 (t, 3 H); MS (ESI) m/z: 393.0 [M+H]+.
[0263] Example 31: A mixture of Example A14 (0.120 g, 0.307 mmol) and TEA (0.043 mL, 0.307 mmol) in THF (3.0 mL) was treated with phenyl isocyanate (0.040 g, 0.337 mmol) and stirred at RT for 4 h. Over the course of the next 4 days the mixture was treated with additional phenyl isocyanate (0.056 mL) and stirred at RT. The resulting solid was filtered, rinsed with THF, then triturated with MeOH to afford l-(4-bromo-5-(l-ethyl-7-(methylamino)-2-oxo- 1 ,2-dihydro- 1 ,6-naphthyridin-3 -yl)-2-fluorophenyl)-3 -phenylurea (101 mg, 64.5% yield) as a bright white solid. 1H NMR (400 MHz, DMSO-<¾): δ 9.09 (s, 1 H), 8.68 (s, 1 H), 8.41 (s, 1 H), 8.17 (d, 1 H), 7.70 (s, 1 H), 7.65 (d, 1 H), 7.41 (d, 2 H), 7.27 (m, 2 H), 7.03 (m, 1 H), 6.96 (t, 1 H), 6.23 (s, 1 H), 4.13 (q, 2 H), 2.86 (d, 3 H), 1.20 (t, 3 H); MS (ESI) m/z: 510.1 [M+H]+.
^ World Health Organization (2019). “International nonproprietary names for pharmaceutical substances (INN): recommended INN: list 81”. WHO Drug Information. 33 (1): 106. hdl:10665/330896. License: CC BY-NC-SA 3.0 IGO.
^“Ripretinib” (PDF). United States Adopted Name (USAN) Drug Finder. Retrieved 17 May 2020.
Clinical trial number NCT03353753 for “Phase 3 Study of DCC-2618 vs Placebo in Advanced GIST Patients Who Have Been Treated With Prior Anticancer Therapies (invictus)” at ClinicalTrials.gov
Triheptanoin is a source of heptanoate fatty acids, which can be metabolized without the enzymes of long chain fatty acid oxidation.4 In clinical trials, patients with long chain fatty acid oxidation disorders (lc-FAODs) treated with triheptanoin are less likely to develop hypoglycemia, cardiomyopathy, rhabdomyolysis, and hepatomegaly.1,2 Complications in lc-FAOD patients are reduced from approximately 60% to approximately 10% with the addition of triheptanoin.2
Triheptanoin was granted FDA approval on 30 June 2020.4
Triheptanoin, sold under the brand name Dojolvi, is a medication for the treatment of children and adults with molecularly confirmed long-chain fatty acid oxidation disorders (LC-FAOD).[1][2][3]
The most common adverse reactions include abdominal pain, diarrhea, vomiting, and nausea.[1][2][3]
Triheptanoin was approved for medical use in the United States in June 2020.[4][2][3]
Since triheptanoin is composed of odd-carbon fatty acids, it can produce ketone bodies with five carbon atoms, as opposed to even-carbon fatty acids which are metabolized to ketone bodies with four carbon atoms. The five-carbon ketones produced from triheptanoin are beta-ketopentanoate and beta-hydroxypentanoate. Each of these ketone bodies easily crosses the blood–brain barrier and enters the brain.
Medical uses
Dojolvi is indicated as a source of calories and fatty acids for the treatment of children and adults with molecularly confirmed long-chain fatty acid oxidation disorders (LC-FAOD).[1][2]
Triheptanoin was approved for medical use in the United States in June 2020.[4][2]
The FDA approved triheptanoin based on evidence from three clinical trials (Trial 1/NCT018863, Trial 2/NCT022141 and Trial 3/NCT01379625).[3] The trials enrolled children and adults with LC-FAOD.[3] Trials 1 and 2 were conducted at 11 sites in the United States and the United Kingdom, and Trial 3 was conducted at two sites in the United States.[3]
Trial 1 and Trial 2 were used to evaluate the side effects of triheptanoin.[3] Both trials enrolled children and adults diagnosed with LC-FAOD.[3] In Trial 1, participants received triheptanoin for 78 weeks.[3] Trial 2 enrolled participants from other trials who were already treated with triheptanoin (including those from Trial 1) as well as participants who were never treated with triheptanoin before.[3] Trial 2 is still ongoing and is planned to last up to five years.[3]
The benefit of triheptanoin was evaluated in Trial 3 which enrolled enrolled children and adults with LC-FAOD.[3] Half of the participants received triheptanoin and half received trioctanoin for four months.[3] Neither the participants nor the investigators knew which treatment was given until the end of the trial.[3] The benefit of triheptanoin in comparison to trioctanoin was assessed by measuring the changes in heart and muscle function.[3]
Names
Triheptanoin is the international nonproprietary name.[17]
^ World Health Organization (2019). “International nonproprietary names for pharmaceutical substances (INN): recommended INN: list 82”. WHO Drug Information. 33 (3): 694. hdl:10665/330879. License: CC BY-NC-SA 3.0 IGO.
Further reading
de Almeida Rabello Oliveira M, da Rocha Ataíde T, de Oliveira SL, de Melo Lucena AL, de Lira CE, Soares AA, et al. (March 2008). “Effects of short-term and long-term treatment with medium- and long-chain triglycerides ketogenic diet on cortical spreading depression in young rats”. Neurosci. Lett. 434 (1): 66–70. doi:10.1016/j.neulet.2008.01.032. PMID18281154. S2CID7754768.
“Triheptanoin”. Drug Information Portal. U.S. National Library of Medicine.
Clinical trial number NCT01379625 for “Study of Triheptanoin for Treatment of Long-Chain Fatty Acid Oxidation Disorder (Triheptanoin)” at ClinicalTrials.gov
Originator Japan Tobacco Developer Japan Tobacco; JW Pharmaceutical Class Acetic acids; Amides; Antianaemics; Pyridones; Small molecules; Triazoles Mechanism of Action Hypoxia-inducible factor-proline dioxygenase inhibitors
Preregistration Anaemia
27 Dec 2019 Japan Tobacco and SalubrisBio enter into a development and marketing agreement for enarodustat (JTZ 951) in China, Hong Kong, Macau and Taiwan for Anaemia 29 Nov 2019 Preregistration for Anaemia in Japan (PO) 31 Oct 2019 Phase I development in Anaemia is ongoing in USA
Enarodustat is a potent and orally active factor prolyl hydroxylase inhibitor, with an EC50 of 0.22 μM. Enarodustat has the potential for renal anemia treatment
Inhibition of hypoxia inducible factor prolyl hydroxylase (PHD) represents a promising strategy for the discovery of a next generation treatment for renal anemia. We identified several 5,6-fused ring systems as novel scaffolds of the PHD inhibitor on the basis of pharmacophore analysis. In particular, triazolopyridine derivatives showed potent PHD2 inhibitory activities. Examination of the predominance of the triazolopyridines in potency by electrostatic calculations suggested favorable π–π stacking interactions with Tyr310. Lead optimization to improve the efficacy of erythropoietin release in cells and in vivo by improving cell permeability led to the discovery of JTZ-951 (compound 14), with a 5-phenethyl substituent on the triazolopyridine group, which increased hemoglobin levels with daily oral dosing in rats. Compound 14 was rapidly absorbed after oral administration and disappeared shortly thereafter, which could be advantageous in terms of safety. Compound 14 was selected as a clinical candidate.
Certain glycopyrronium salts and related compounds, as well as processes for making and methods of using these glycopyrronium salts and related compounds, are known. See, for example, US Patent No. 8,558,008, which issued to assignee Dermira, Inc. See also, for example, US Patent No. 2,956,062, which issued to assignee Robins Co Inc. A H. See also, for example, International Patent Application Publication Nos. WO 98/00132 Al and WO 2009/00109A1, both of which list applicant Sepracor, Inc., as well as US Patent Nos. 6,063,808 and 6,204,285, both of which issued to assignee Sepracor, Inc. Certain methods of treating hyperhidrosis using glycopyrronium salts and related compounds are known. See, for example GB 1,080,960. Certain forms of applying glycopyrrolate compounds to a subject are known. See, for example US Patent Nos. 6,433,003 and 8,618,160, both of which issued to assignee Rose U; also US Patent Nos. 7,060,289; 8,252,316; and 8,679,524, which issued to PurePharm, Inc.
[0004] One glycopyrronium salt which is useful in certain medical applications is the following compound:
[0005] As illustrated above, the absolute configuration at the three asymmetric chiral positions is 2R3’R1’RS. This means that the carbon indicated with the number, 2, has the stereochemical R configuration. The carbon indicated with the number, 3′, also has the stereochemical R configuration. The quatemary ammonium nitrogen atom, indicated with a positive charge, may have either the R or the S stereochemical configuration. As drawn, the compound above is a mixture of two diastereoisomers.
[0006] Certain processes for making glycopyrronium salts are known. However, these processes are not as safe, efficient, stereospecific, or stereoselective as the new processes disclosed herein, for example with respect to large-scale manufacturing processes. Certain publications show that higher anticholinergic activity is attributed to the 2R3’R configuration. However, to date, processes for making the 2R3’R isomers, as well as the 2R3’R1’R isomers are low yielding, involve too many reaction steps to be economically feasible, use toxic materials, and/or are not sufficiently stereospecific or stereoselective with respect to the products formed.
EXAMPLE 2
[0179] The below synthetic description refers to the numbered compounds illustrated in FIG. 2. Numbers which refer to these compounds in FIG. 2 are bolded and underlined in this Example.
[0180] Synthesis of R(-)-Cyclopentylmandelic acid (4)
[0181] R(-)-cyclopentylmandelic acid (compound 4) can be synthesized starting with
R(-)-mandelic acid (compound 1) according to Example 1.
[0182] Step 1 : Making Compound 2.
[0183] R(-)-mandelic acid (1) was suspended in hexane and mixed with pivaldehyde and a catalytic amount of trifluoromethanesulfonic acid at room temperature to form a mixture. The mixture was warmed to 36 °C and then allowed to react for about 5 hours. The mixture was then cooled to room temperature and treated with 8% aqueous sodium bicarbonate. The aqueous layer was removed and the organic layer dried over anhydrous sodium sulfate. After filtration and removal of the solvent under vacuum, the crude product was recrystallized to give (5R)-2-(tert-butyl)-5-phenyl-l,3-dioxolan-4-one (compound 2) in 88% yield (per S-enantiomer yield).
[0184] Step 2: Making Compound 3.
[0185] Compound 2 was reacted with lithium hexamethyl disilazide (LiHMDS) in hexane at -78 °C under stirring for one hour. Next, cyclopentyl bromide was added to the reaction mixture including compound 2 and LiHMDS . The reaction was kept cool for about four (4) hours and then slowly warmed to room temperature and allowed to react for at least twelve (12) more hours. The resulting mixture was then treated with 10% aqueous ammonium chloride. The aqueous layer was discarded and the organic layer dried over anhydrous sodium sulfate. The solvent was removed under vacuum and the residue recrystallized from hexane to give pure product (5R)-2-(tert-butyl)-5-cyclopentyl-5-phenyl- l,3-dioxolan-4-one (3) in 63% yield (per S-enantiomer yield).
[0186] Step 3: Making Compound 4.
[0187] R(-)-cyclopentylmandelic acid (compound 4) was prepared by providing compound 3 in aqueous methanolic potassium hydroxide at 65 °C for four hours. After cooling this mixture to room temperature and removing the methanol under vacuum, the aqueous solution was acidified with aqueous hydrochloric acid. The aqueous solution was then extracted twice with ethyl acetate and the organic phase dried with anhydrous sodium sulfate. After removing the solvent and performing a recrystallization, pure R(-)- cyclopentylmandelic acid (compound 4) was obtained in 62% yield (based on S-enantiomer yield).
[0188] Next, a racemic mixture of l -methyl-3-pyrridinol (20) was provided:
[0189] Synthesis of 2R3 ‘R-glycopyrrolate base (8)
[0190] Step 4: Making Compound 8.
[0191] Enantiomerically pure R(-)-cyclopentylmandelic acid (4) was coupled to racemic l-methyl-3-pyrridinol (20) using 1, 1 -carbonyldiimideazole (CDI) activated esterification to make an enantiomerically pure mixture of the following erythro- and threo- glycopyrrolate bases (compounds 8 and 21, respectively):
[0192] The 2R3’R-glycopyrrolate base (compound 8) was then resolved using the 5- nitroisophthalate salt procedure in Finnish Patent 49713, to provide enantiomerically pure 2R3 Έ. {erythro) as well as pure 2R3 ‘S {threo). In this example, the 2R3 ‘S {threo) was discarded. The 2R3 Έ. {erythro) was separated as stereomerically pure compound 8.
[0193] Step 6: Making Compound 9.
[0194] The glycopyrrolate base, compound 8, was treated in dry acetonitrile with methyl bromoacetate at room temperature under stirring for three (3) hours. The crude product was dissolved in a small volume of methylene chloride and poured into dry ethyl ether to obtain a precipitate. This procedure was repeated three times to provide (3R)-3-((R)- 2-cyclopentyl-2-hydroxy-2-phenylacetoxy)-l -(2-ethoxy-2-oxoethyl)-l-methylpyrrolidin-l – ium bromide, also known as 3′(R)-[R-Cyclopentylphenylhydroxyacetoy]- -ethyl- l ‘methoxycarbonylpyrrolidinium bromide (compound 9) in 89% yield. Compound 9 included the following stereoisomers:
ClassAntiparasitics; Heterocyclic compounds; Pyridines; Small molecules
Mechanism of ActionChelating agents; Metalloprotease inhibitors
Registered Pediculosis
27 Jul 2020Registered for Pediculosis (In adolescents, In children, In infants, In adults) in USA (Topical)
18 Jun 2020FDA assigns PDUFA action date of 12/08/2020 for Abametapir for Pediculosis (Dr Reddy’s Laboratories website, June 2020)
31 Mar 2019Abametapir is still in preregistration phase for Pediculosis in USA
Abametapir is a novel pediculicidal metalloproteinase inhibitor used to treat infestations of head lice.4 The life cycle of head lice (Pediculus capitis) is approximately 30 days, seven to twelve of which are spent as eggs laid on hair shafts near the scalp.2 Topical pediculicides generally lack adequate ovicidal activity,2 including standard-of-care treatments such as permethrin, and many require a second administration 7-10 days following the first to kill newly hatched lice that resisted the initial treatment. The necessity for follow-up treatment may lead to challenges with patient adherence, and resistance to agents like permethrin and pyrethrins/piperonyl butoxide may be significant in some areas.3
Investigations into novel ovicidal treatments revealed that several metalloproteinase enzymes were critical to the egg hatching and survival of head lice, and these enzymes were therefore identified as a potential therapeutic target.1 Abemetapir is an inhibitor of these metalloproteinase enzymes, and the first topical pediculicide to take advantage of this novel target. The improved ovicidal activity (90-100% in vitro) of abemetapir allows for a single administration, in contrast to many other topical treatments, and its novel and relatively non-specific mechanism may help to curb the development of resistance to this agent.1
Abametapir was first approved for use in the United States under the brand name Xeglyze on July 27, 2020.6
Abametapir, sold under the brand name Xeglyze, is a medication used for the treatment of head lice infestation in people six months of age and older.[1][2]
The most common side effects include skin redness, rash, skin burning sensation, skin inflammation, vomiting, eye irritation, skin itching, and hair color changes.[2]
Abametapir is indicated for the topical treatment of head lice infestation in people six months of age and older.[1][2]
History
The U.S. Food and Drug Administration (FDA) approved abametapir based on evidence from two identical clinical trials of 699 participants with head lice.[2] The trials were conducted at fourteen sites in the United States.[2]
The benefit and side effects of abametapir were evaluated in two clinical trials that enrolled participants with head lice who were at least six months old.[2]
About half of all enrolled participants was randomly assigned to abametapir and the other half to placebo.[2] Abametapir lotion or placebo lotion were applied once as a ten-minute treatment to infested hair.[2] The benefit of abametapir in comparison to placebo was assessed after 1, 7 and 14 days by comparing the counts of participants in each group who were free of live lice.[2]
SYN
Ronald Harding, Lewis David Schulz, Vernon Morrison Bowles, “Pediculicidal composition.” WIPO Patent WO2015107384A2, published July, 2015.
DRUG APPROVALS BY DR ANTHONY MELVIN CRASTO
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Fig.1 Biosynthesis of pineal methoxyindoles from serotonin
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This article incorporates text from this source, which is in the 
New Drug Approvals 
