Tribromoborane-methyl sulfide → 1-Methyl-2-(methylamino)-1H-benzo[d]imidazol-4-ol

Participants

Reaction Steps

To a suspension of 4-benzyloxy-1-methyl-2-methylamino-1H-benzimidazole (150 mg) in dichloromethane (2 ml) was added boron tribromide-methyl sulfide complex (211 mg) in dryice-aceton bath, and the mixture was stirred for 1 hour under ice-cooling and then at ambient temperature overnight. To the reaction mixture were added chloroform-methanol (3:1, v/v) and saturated sodium bicarbonate solution, and insoluble material was filtered off. The separated organic layer was concentrated in vacuo. The residue was purified by preparative thin layer chromatography (chloroform:methanol=8:1, v/v) to give 4-hydroxy-1-methyl-2-methylamino-1H-benzimidazole (49 mg).

Provenance & Evidence