abstract |
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-l-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[l,2,4]triazolo[4,3-a]pyrazin- 7(8H)-yl]-l- (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-l-(3-(trifluoromethyl)-5,6-dihydro-[l,2,4]triazolo[4,3-a]pyrazin- 7(8H)-yl)-4-(2,,4,5-trifluorophenyl) butan-l-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 |