Formic Acid → HCID 20135407, compound

Participants

Reaction Conditions

Reaction Steps

Acetic anhydride (7.8 ml) and formic acid (12.5 ml) were mixed together and stirred at -10° C. for 1 hour. This solution now containing formic-acetic mixed anhydride was added to a solution of 4-bromo-N,N-dimethyl-1,2,6,7-tetrahydrobenzo[b]pyrrolo[3,2,1-jk][1,4]benzodiazepine-6-propanamine (21.3 g) in chloroform (250 ml) at room temperature in one portion. The resulting solution was shaken for 30 minutes The reagent and solvent were removed on a rotary evaporator to give a foam-oil mixture. This was dissolved into dichloromethane and water and the mixture was basified with 10% sodium hydroxide. The organic phase was separated, washed with water and brine (2×250 ml) and dried over anhydrous magnesium sulfate. Removal of the solvent gave an oily crude product. Purification was conducted by flash chromatography on silica gel (140 g) eluted with 2 liters of dichloromethane, 2 liters of 1% methanol/dichloromethane and 2 liters of 2% methanol/dichloromethane. Fractions containing the pure product were combined and concentrated to afford 14.7 g of solid. Recrystallization from ethanol (40 ml) at 0° C. gave 10.6 g of crystals, m.p. 126°-127° C.

Provenance & Evidence