Novel process for preparation of empagliflozin or its co-crystals, solvates and their polymorphs thereof

on of Compound of Formula III

[0289]The residue of compound of Formula IV was dissolved in a mixture of acetonitrile (300 ml) and dichloromethane (300 ml) at 25-35° C. Triethylsilane (129.2 gr) was added at 25-35° C. and the temperature of the reaction mass was cooled to −25 to −35° C. Borontrifluoride-diethyletherate (158.1 gr) was added to the reaction mass at −40 to −30° C. and stirred for 15 to 20 min. Temperature of the reaction mass was raised to 0° C. and further maintained with stirring for 3 to 4 hrs. Water was added, and the layers were separated and the aqueous layer was extracted with 2-methyltetrahydrofuran or ethyl acetate, combined the organic layers and washed with water, 8% sodium bicarbonate solution and further with 10% brine solution and dried over sodium sulphate. The organic layer was distilled completely under vacuum at below 45° C. and co-distilled with n-heptane and purified by ethyl acetate to obtain the title compound as a solid.

Yield: 40 gms

on of Empagliflozin of Formula I

[0290]The residue of compound of Formula III was dissolved in N,N-Dimethylformamide (210 ml) at 25-35° C. Cesium carbonate (74.5 gr) and R-Tosyl tetrahydrofuran (26.8 gr) was added. Raised the temperature of the reaction mass to 45° C. to 50° C. and maintained for 12-24 hrs. Water and dichloromethane (525 ml) were added to the reaction mass and adjust the pH of the reaction mass to 7.0 to 8.0 using 5% hydrochloric acid solution. Separate the layers and extract the aqueous layer with dichloromethane. Organic layers were combined and washed with water, 10% sodium chloride, and dried over sodium sulphate. Filtered the solid and dried over vacuum to obtain empagliflozin as a residue.

Example 7: Preparation of Empagliflozin

[0291]The residue of compound of Formula III was dissolved in dimethylsulphoxide (210 ml) at 25-35° C. Cesium carbonate (74.5 gr) and R-Tosyl tetrahydrofuran (26.8 gr) was added. Raised the temperature of the reaction mass to 45° C. to 50° C

on of Empagliflozin-DL-Pipecolic Acid

[0292]The residue of empagliflozin, obtained according to Example 5 was added to DL-pipecolic acid (24 gr) and water (21 mL) at 80-85° C. and stirred the reaction mass for about 1 hr at 80-85° C. The reaction mass was allowed to cool to 25-35° C. and stirred for 24-48 hrs. Filtered the reaction mass and washed with n-butanol and dried the product at 45-50° C. under vacuum for 6-8 hrs.

Yield: 50 gms. HPLC: NLT 99.0%