5-Methylisatoic anhydride → 3,4-dihydro-3,7-dimethyl-1H-1,4-benzodiazepine-2,5-dione

Participants

Reaction Conditions

Reaction Steps

A mixture of 17.7 parts of 6-methyl-4H-3,1-benzoxazine-2,4(1H)-dione, 15.0 parts of methyl 2-aminopropanoate monohydrochloride and 62.7 parts of pyridine was refluxed for 6 hours under argon. The reaction mixture was cooled at −10° C. for 1 hour. The precipitate was filtered off, rinsed with water, triturated in ethanol and rinsed with ethanol and 1,1′-oxybisethane, yielding 10.32 parts (50.5%) of 3,4-dihydro-3,7-dimethyl-1H-1,4-benzodiazepine-2,5-dione (interm. 43).

Provenance & Evidence