反应详情

A solution of 50.1 parts of 6-chloro-5,7-dimethyl-4-oxo-4H-1-benzopyran-2-carboxylic acid ethyl ester in 750 parts of warm ethanol was saturated with dry ammonia. After 2 hours a solid had precipitated out and the slurry was heated on the steam bath to remove excess ammonia. The solid was filtered off and crystallised from dimethylformamide to give 42.3 parts of 6-chloro-5,7-dimethyl-4-oxo-4H-1-benzopyran-2-carboxamide, melting point >300° C.

1. customAfter 2 hours a solid had precipitated out
2. temperaturethe slurry was heated on the steam bath
3. customto remove excess ammonia
4. filtrationThe solid was filtered off
5. customcrystallised from dimethylformamide