1H-Benzimidazole, 1-methyl- → (1-methyl-1H-1,3-benzodiazol-2-yl)methanol

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Reaction Steps

1-Methylbenzimidazole (5.0 g, 0.038 mol) was stirred at reflux in 37 wt % aqueous formaldehyde (50 ml) for 24 h. The solution was allowed to cool to room temperature then basified with saturated sodium hydrogen carbonate solution and then extracted with. dichloromethane (3×50 ml). The combined organic layers were dried over magnesium sulfate and were concentrated in vacuo. The residue was purified by flash chromatography on silica gel, eluting with 2.5 to 10% methanol in dichloromethane. The resultant semi-solid was triturated with isohexane to yield a solid, which was then recrystallised from ethyl acetate/isohexane, yielding (1-methyl-1H-benzimidazol-2-yl)methanol as a white solid (0.71 g). Data for the title compound: 1H NMR (400 MHz, CDCl3) δ 3.81 (3H, s), 4.89 (2H, s), 7.26 (3H, m), 7.69 (1H, m); MS (ES+) m/e 163 [MH]+.

Provenance & Evidence