Chloroacetic anhydride → (S)-8-bromo-1-(5-chloromethyl-1,2,4-oxadiazol-3-yl)-11,12,13,13a-tetrahydro-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepin-9-one

Participants

Reaction Steps

11.5 g (30.6 mmol) of (S)-8-bromo-9-oxo-11,12, 13,13a-tetrahydro-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxamidoxime were treated with 6.02 g (35.2 mmol) of chloroacetic anhydride in 60 ml of N,N-dimethylformamide at room temperature for 1 hour and at 105° for 3 hours. After evaporating the solvent the residue was dissolved in methylene chloride and the solution was washed with saturated sodium bicarbonate solution. 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 10.2 g (76%) of (S)-8-bromo-1-(5-chloromethyl-1,2,4-oxadiazol-3-yl)-11,12,13,13a-tetrahydro-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepin-9-one of m.p. 242°-244°.

Provenance & Evidence