Dimethylformamide → 5,6-dihydro-5-methyl-3-(3-phthalimidomethyl-1,2,4-oxadiazol-5-yl)-4H-imidazo[1,5-a][1,4]benzodiazepin-6-one

Participants

Reaction Steps

15 g (5.83 mmol) of 5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a]-[1,4]benzodiazepine-3-carboxylic acid were dissolved in 100 ml of N,N-dimethylformamide, treated portionwise with 11.3 g (7 mmol) of 1,1'-carbonyldiimidazole and stirred at 70° for 20 min. After adding 19.2 g (8.75 mmol) of phthaloylglycine amidoxime the mixture was stirred at 80° for 3 hours, 5 ml of trifluoroacetic acid were added and the mixture was stirred at 110° overnight. The reaction mixture was concentrated and the residue was chromatographed on 200 g of silica gel while eluting with ethyl acetate. There were obtained 13 g (50%) of 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. 239°-240°.

Provenance & Evidence