Water → Carbonic acid, 6-(5-chloro-2-pyridinyl)-6,7-dihydro-7-oxo-5H-pyrrolo(3,4-b)pyrazin-5-yl phenyl ester

Participants

Reaction Conditions

Reaction Steps

Phenyl chloroformate (141 g.) is added, with stirring and whilst keeping the temperature at about 5° C., to a suspension of 6-(5-chloropyrid-2-yl)-5-hydroxy-7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazine (158 g.) in anhydrous pyridine (1,580 cc.). When the addition is complete, the reaction mixture is heated to a temperature of about 60° C. The heating is continued for one hour. Water (4,750 cc.) is added to the reaction mixture after it has been cooled to a temperature of about 20° C. The product which crystallises is filtered off and washed with water (2×250 cc.), acetonitrile (150 cc.) and diisopropyl ether (250 cc.). After drying, 6-(5-chloropyrid-2-yl)-7-oxo-5-phenoxycarbonyloxy-6,7-dihydro-5H-pyrrolo[3,4-b]-pyrazine (169 g.), which melts at 193° C., is obtained.

Provenance & Evidence