反应详情

A mixture of 5,6-dimethyl-1-(4-nitrobenzyl)-1H-benzimidazole (2.5 g), 10% palladium carbon (300 mg), ethanol (150 ml) and tetrahydrofuran (150 ml) was stirred under a hydrogen atmosphere at room temperature for 4 hrs. Palladium carbon was removed from the reaction mixture by filtration, and the filtrate was concentrated. Recrystallization of the residue from ethyl acetate-methanol gave 1-(4-aminobenzyl)-5,6-dimethyl-1H-benzimidazole (1.88 g, 84%) as colorless prism crystals. melting point: 238-239° C.

1. customPalladium carbon was removed from the reaction mixture by filtration
2. concentrationthe filtrate was concentrated
3. customRecrystallization of the residue from ethyl acetate-methanol