Processes for the preparation of sitagliptin and pharmaceutically acceptable salts thereof

Abstract

There is provided salts and polymorphs of sitagliptin, processes for the preparation thereof, and pharmaceutical composition comprising the same.

1 - 20 . (canceled) 
     
     
         21 . Crystalline Sitagliptin acetate. 
     
     
         22 . A process for preparation of crystalline Sitagliptin acetate of  claim 21 , comprising
 a) providing a solution of Sitagliptin acetate in a solvent,   b) isolating the Sitagliptin acetate   c) recovering the crystalline sitagliptin acetate and optionally drying it.   
     
     
         23 . The process of  claim 22  wherein in step a) suitable solvent is selected from alcohols, halogenated hydrocarbons, esters, ketones, hydrocarbons, ethers, polar aprotic solvents or their mixtures. 
     
     
         24 . The process of  claim 23  wherein in step a) solvent is selected from methanol, ethanol, isopropanol, n-butanol and mixtures thereof. 
     
     
         25 . The process of  claim 22  wherein in step b) isolation involve processes selected from cooling, stirring, distillation, addition of solvent or any combination thereof. 
     
     
         26 . The process of  claim 22  wherein in step c) recovery involves techniques like filtration, centrifugation and slow evaporation. 
     
     
         27 . The process of  claim 22  wherein step of drying is performed at the temperature range of 20° C. to 80° C. 
     
     
         28 . The process of  claim 22  wherein drying is performed at the temperature range of 30° C. to 60° C. 
     
     
         29 . The process of  claim 27  wherein drying is performed at 80° C. 
     
     
         30 . The process of  claim 28  wherein drying is performed at 60° C. 
     
     
         31 . The process of  claim 24  wherein the solvent is isopropyl alcohol. 
     
     
         32 . The process of  claim 31  wherein drying is performed at 60° C. 
     
     
         33 . The process of  claim 31  wherein drying is performed at 80° C. 
     
     
         34 . The process of  claim 32  wherein drying time is 3.5 hours. 
     
     
         35 . The process of  claim 33  wherein drying time is 3.5 hours.