Hydrochloric Acid → HCID 22485170, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of methyl 4-chloro-1,2-dimethyl-1H-benzimidazole-5-carboxylate (1.07 g) in anhydrous tetrahydrofuran (11 ml) was added portionwise lithium borohydride (198 mg) at room temperature and the mixture was stirred for 2 hr and heated to 60° C. Thereafter, lithium borohydride (99 mg) was added 3 times at 1 hr intervals. The reaction mixture was ice-cooled and adjusted to pH 2 with 1N hydrochloric acid. The mixture was stirred at room temperature for 30 min, and chloroform was added to the mixture. The precipitated crystals were collected by filtration to give 4-chloro-5-hydroxymethyl-1,2-dimethyl-1H-benzimidazole as colorless crystals (487 mg). The filtrate was extracted 6 times with chloroform:methanol=5:1. The organic layer was dried over anhydrous magnesium sulfate, filtrated and concentrated. The residue was crystallized from isopropyl ether to give the objective product as colorless crystals (417 mg).

Provenance & Evidence