Chloroacetic anhydride → HCID 22914481, compound

Participants

Reaction Steps

15.3 g (50 mmol) of 7-chloro-5-methyl-6-oxo-5,6-dihydro-4H-imidazo[1,5-a][1,4]benzodiazepin-3-carboxylic acid hydrazide were stirred at room temperature overnight in 160 ml of N,N-dimethylformamide with 9.41 g (55 mmol) of chloroacetic anhydride. After evaporating the solvent the residue was stirred at room temperature over the weekend with 100 ml of a 10% solution of phosphorus pentoxide in methanesulphonic acid. The reaction mixture was treated with ice, made alkaline with conc. sodium hydroxide solution and extracted four times with methylene chloride. By drying the organic phase over magnesium sulfate, evaporation of the solvent and chromatography of the residue on silica gel while eluting with ethyl acetate there were obtained 9.7 g (53%) of 7-chloro-3-(5-chloromethyl-1,3,4-oxadiazol-2-yl)-5-methyl-5,6-dihydro-4H-imidazo[1,5-a][1,4]benzodiazepin-6-one of m.p. 201°-203°.

Provenance & Evidence