Process for preparation of (2R)-4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro [1,2,4]-triazolo[4,3-a]pyrazin-7(8H)-yl]-l-(2,4,5-trifluorophenyl)butan-2-amine and new impurities in preparation thereof

摘要

The present invention relates to synthesis of beta-amino acid derivatives of formula (I) and its salts of formula (Ia) by a novel process. The process comprises the reduction of a protected or unprotected prochiral beta-amino acrylic acid or derivative there of, by using borane containing reducing agents at atmospheric pressure. The resulting racemic beta-amino compound is resolved to a pure stereoisomer of formula (I), specifically to (2R)-4-oxo-4-[3-Ctrifluoromethyl)-5,6-dihydrol[1,2,4]triazolo[4,3-alpyrazin-7(8H)-yl]-1-(2,4,4-trifluorophenyl)butan-2-amine. In an embodiment the invention disclosed polymorphic forms of formula (I), phosphate salt of formula (I) and also a Dibenzoyl-L-tartaric acid salt of formula (I).