Phenyl chloroformate → 6-(7-chloro-1,8-naphthyridin-2-yl)-7-oxo-5-phenoxycarbonyloxy-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazine

Participants

Reaction Conditions

Reaction Steps

6-(7-Chloro-1,6-naphthyridin-2-yl)-7-oxo-5-phenoxycarbonyloxy-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazine can be prepared by adding phenyl chloroformate (9.4 g.) to a suspension of 6-(7-chloro-1,8-naphthyridin-2-yl)5-hydroxy-7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazine (6.3 g.) in anhydrous pyridine (63 cc.), with stirring and whilst keeping the temperature at about 5° C. When the addition is complete, the reaction mixture is gradually heated to 60° C. and this temperature is maintained for 1 hour. The reaction mixture is cooled and is then poured into distilled water (350 cc.) whilst keeping the temperature at about 10° C. The insoluble product is filtered off, and washed successively with water (120 cc.), acetonitrile (40 cc.) and diisopropyl ether (40 cc.). After drying, 6-(7-chloro-1,8-naphthyridin-2-yl)-7-oxo-5-phenoxycarbonyloxy-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazine (7.2 g.), melting at 270° C., is obtained.

Provenance & Evidence