Dimethylformamide → HCID 22914227, compound

Participants

Reaction Steps

38.8 g (133 mmol) of 7-chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]-benzodiazepine-3-carboxylic acid were dissolved in 200 ml of N,N-dimethylformamide, treated portionwise with 23.7 g (146 mmol) of 1,1'-carbonyldiimidazole and stirred at 70° for 20 min. After adding 43.73 g (199.5 mmol) of phthaloylglycine amidoxime the mixture was stirred at 90° for 1 hour. 1.5 ml of trifluoroacetic acid were added and the mixture was stirred at 90° overnight and at 120° for a further 3 hours. The suspension obtained was concentrated to half of its volume and cooled, and the precipitated crystals were filtered off. There were obtained 35.3 g (56%) of 7-chloro-5,6-dihydro-5-methyl-3-(3-phthalimidomethyl-1,2,4-oxadiazol-5-yl)-4H-imidazo[1,5-a][1,4]benzodiazepin-6-one of m.p. 237°-239°.

Provenance & Evidence