Process for preparing 6-(5-chloropyrid-2-yl)-5-hydroxy-7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazine

Preparation of 6-(5-chloropyridin-2-yl)-5-hydroxy-7-oxo-6,7-dihydro-5H-pyrrolo(3,4-b)pyrazine (I) comprises treatment of a pyrazine derivative (II) with sodium borohydride in an aqueous organic amide. Preparation of 6-(5-chloropyridin-2-yl)-5-hydroxy-7-oxo-6,7-dihydro-5H-pyrrolo(3,4-b) -pyrazine of formula (I) by treatment of a pyrazine derivative of formula (II) with sodium borohydride in an aqueous organic amide. In the present invention there is disclosed a process for preparing 6-(5-chloropyrid-2-yl)-5-hydroxy-7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]py razine of the general formula I from 6-(5-chloropyrid-2-yl)-5,7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazine of the general formula II, by reacting thereof with sodium borohydride in a liquid organic amide in the presence of water and at a temperature ranging from -10 degC to 70 degC. Způsob přípravy 6-(5-chlorpyrid-2-yl)-5-hydroxy-7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazinu vzorce I z 6- (5-chlorpyrid-2-yl)-5,7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazinu vzorce II, reakcí s borohydridem sodným v kapalném organickém amidu za přítomnosti vody při teplotách od -10 .degree.C do 70 .degree.C.ŕ