1-Cyclobutyl-piperidin-4-ol (1.6 grams, 10 mmol) in tetrahydrofuran (20 mL) was treated with cooled and stirred suspension of sodium hydride (0.9 grams, 18 mmol) in tetrahydrofuran (20 mL) slowly over a period of 30 minutes; the reaction mixture was stirred for 1 hour. A solution of 2-Bromo-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid tert-butyl ester (3 grams, 9 mmol, obtained in preparation 1) in tetrahydrofuran (30 mL) was added drop wise over a period of 15 minutes and refluxed the reaction for 6 hours. Reaction mass was quenched with ice cold water and the product was extracted with ethyl acetate (3×50 mL). Combined organics were washed with water followed by brine and dried over anhydrous sodium sulphate. Organic volatiles were evaporated under vacuum. The residue was purified by flash chromatography (ethylacetate/n-hexane, 1/1) to obtain the title compound (2.0 grams).

¹H-NMR (δ ppm): 1.48 (9H, s), 1.65-1.72 (2H, m), 1.85-1.92 (4H, m), 2.01-2.07 (4H, m), 2.18-2.19 (2H, m), 2.57 (2H, m), 2.62-2.66 (2H, m), 2.71-2.75 (1H, m), 3.70 (2H, m), 4.43 (2H, m), 4.93 (1H, m);

Mass (m/z): 394.2 (M+H)⁺.

Step (ii): Preparation of 2-(1-Cyclobutyl-piperidin-4-yloxy)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridineA solution of 2-(1-Cyclobutyl-piperidin-4-yloxy)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid tert-butyl ester (2.0 grams, 5 mmol, obtained in above step) in dichloromethane (30 mL) was treated with trifluroacetic acid (5.0 mL, 50 mmol) at 0° C. Reaction mass was stirred for 4 hours. After completion of reaction, the reaction mass was quenched into ice cold water and adjust pH to 10, by using 40% aqueous sodium hydroxide solution. The product was extracted with dichloromethane (3×50 mL), combined organics were washed with water followed by brine and dried over anhydrous sodium sulphate. Organic volatiles were evaporated under vacuum to obtain the title compound (1.3 grams).

¹H-NMR (δ ppm): 1.68-1.74 (2H, m), 1.85-1.93 (4H, m), 2.06 (4H, m), 2.19 (2H, m), 2.60-2.61 (4H, m), 2.73-2.80 (1H, m), 2.90-3.10 (1H, m), 3.13-3.16 (2H, m), 3.85 (2H, s), 4.90-4.93 (1H, m);

Mass (m/z): 294.2 (M+H)⁺.

Step (iii): Preparation of 1-[2-(1-Cyclobutyl-piperidin-4-yloxy)-6,7-dihydro-4H-thiazolo[5,4-c]pyridin-5-yl]-propan-1-oneA solution of 2-(1-Cyclobutyl-piperidin-4-yloxy)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridine (1.3 grams, 4 mmol, obtained in above step) and triethylamine (1.9 mL, 13 mmol) in dichloromethane (30 mL) was cooled to 0° C. Propionylchloride (0.4 mL, 5 mmol) in dichloromethane (5 mL) was added drop wise over a period of 15 minutes and stirred the reaction for 30 minutes. Reaction mass was poured onto ice cold water and the product was extracted with ethyl acetate (3×50 mL). Combined organics were washed with water followed by brine and dried over anhydrous sodium sulphate. Organic volatiles were evaporated under vacuum. The residue was purified by flash chromatography (methanol/chloroform, 2/98) to obtain the title compound (1.0 gram).

¹H-NMR (δ ppm): 1.17-1.21 (3H, m), 1.65-1.72 (5H, m), 1.87-1.91 (4H, m), 2.01-2.07 (4H, m), 2.22 (1H, m), 2.38-2.45 (2H, m), 2.45 (1H, m), 2.68-2.76 (3H, m), 3.72-3.74 (1H, m), 4.47-4.62 (2H, m), 4.92-4.94 (1H, m).

Mass (m/z): 350.4 (M+H)⁺.

Step (iv): Preparation of 1-[2-(1-Cyclobutyl-piperidin-4-yloxy)-6,7-dihydro-4H-thiazolo[5,4-c]pyridin-5-yl]-propan-1-one tartrateA solution of 1-[2-(1-Cyclobutyl-piperidin-4-yloxy)-6,7-dihydro-4H-thiazolo[5,4-c]pyridin-5-yl]-propan-1-one (0.8 grams, 2.3 mmol, obtained in above step) in methanol (10 mL) was treated with L(+)-Tartaric acid (0.34 grams, 2.3 mmol) at 0° C. Stirred the reaction mass for about 1 hour and the solvent was evaporated under vacuum to dryness. The solids were washed with diethyl ether and dried under vacuum to obtain the title compound (1.1 grams).

¹H-NMR (δ ppm): 1.12-1.20 (3H, m), 1.82-1.87 (2H, m), 2.16-2.32 (7H, m), 2.45-2.55 (2H, m), 2.63-2.66 (3H, m), 2.72 (1H, m), 3.20 (2H, m), 3.47-3.50 (1H, m), 3.66-3.70 (1H, m), 3.81-3.88 (2H, m), 4.45 (2H, s), 4.60 (2H, s), 5.18 (5H, m);

Mass (m/z): 350.4 (M+H)⁺.