PROCESS FOR PREPARING AN INTERMEDIATE OF SITAGLIPTIN VIA ENZYMATIC CONVERSION

摘要

The invention provides a process for preparing 3 -hydroxy-1-(3- (trifluoromethyl)-5,6-dihydro-[l,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)-4-(2,4,5-trifluorophenyl) butan-1-one (Formula I), into its racemic (R/S) form or any of its optically active (S) or (R) forms or enantiomeric excess mixture of any of the forms comprising: a) reacting 4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1- (2,4,5-trifluorophenyl)butan-2-one of formula (III) with a suitable oxidoreductase enzymes or its suitable variants in the presence of suitable conditions and co-factor b) isolating 3-hydroxy-1-(3-(trifluoromethyl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin- 7(8H)-yl)-4-(2,4,5-trifluorophenyl) butan-1-one, into its racemic (R/S) form or any of its optically active (S) or (R) forms or enantiomeric excess mixture of any of the forms