Benzimidazole → 3-(1-benzimidazolyl)-4-(3-indolyl)-1H-pyrrole-2,5-dione

Participants

Reaction Conditions

Reaction Steps

260 mg of a 60% dispersion of sodium hydride in mineral oil were added to a solution of 295 mg of benzimidazole in 10 ml of DMF and the mixture was stirred under nitrogen for 0.5 hour. 582 mg of 3-bromo-4-(3-indolyl)-1H-pyrrole-2,5-dione were added and the mixture was heated to 50° C. for 18 hours. A solution of 767 mg of benzimidazole and 260 mg of sodium hydride in 10 ml of DMF was added and the mixture was heated to 90° C. for 18 hours under nitrogen. The solvent was evaporated and the residue was partitioned between dichloromethane and 2M hydrochloric acid. The precipitate was purified on silica gel with ethyl acetate/petroleum ether. Recrystallization from ethyl acetate gave 25 mg of 3-(1-benzimidazolyl)-4-(3-indolyl)-1H-pyrrole-2,5-dione, m.p. 310°-320° C.

Provenance & Evidence