Methanesulfonic Acid → HCID 22914254, compound

Participants

Reaction Steps

A suspension of 0.50 g (0.00154 mol) of 7-chloro-8-fluoro-5-methyl-6-oxo-5,6-dihydro-4H-imidazo[1,5-a ][1,4]benzodiazepine-3-carboxylic acid hydrazide in 5 ml of N,N-dimethylformamide was treated with 0.33 g (0.00193 mol) of chloroacetic anhydride. The solution obtained was stirred at room temperature for 11/2 hr., whereby a suspension resulted. The suspension was cooled to 0°, treated with 40 ml of ether and suction filtered. The white crystals obtained (0.643 g, m.p. 264°-266° (dec.)) were treated with 4.5 ml of methanesulphonic acid and 0.5 g of phosphorus pentoxide, whereupon the mixture warmed up and the solution was stirred at room temperature for 1 hr. The yellow solution was poured into 75 ml of ice-water, whereupon the mixture was made basic with aqueous sodium hydroxide solution and extracted with methylene chloride. The crystalline product was chromatographed over silica gel with ethyl acetate as the eluent. There was obtained 0.193 g (33%) of 7-chloro-3-(5-chloromethyl-1,3,4-oxadiazol-2-yl)-8-fluoro-5-methyl-5,6-dihydro-4H-imidazo[1,5-a][1,4]benzodiazepin-6-one as white crystals; m.p. :234°-236°.

Provenance & Evidence