50591-22-5

1-methyl-1H-benzimidazol-5-ol is a useful reactant for the preparation of substituted azaquinazolinones as modulators of GHSr-1a for the treatment of type II diabetes and obesity

Boron tribromide (3.1 g, 12.33 mmol) was slowly added dropwise to a solution of 5-methoxy-1-methyl-1H-benzo[d]imidazole (500 mg, 3.08 mmol) in dichloromethane (6 mL) at 0 °C. After the dropwise addition was completed, the reaction mixture was kept at 0 °C and stirring was continued for 2 hours. Subsequently, the reaction was quenched by slow addition of ice water (50 mL). The reaction mixture was extracted with dichloromethane (2 x 20 mL). The organic layers were combined, washed with brine (30 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure to afford 1-methyl-1H-benzimidazol-5-ol (100 mg, 21.9% yield) as a white solid, which could be used in the subsequent reaction without further purification.LCMS (m/z): 149.1 ([M+H]+).

[1] Patent: WO2014/100730, 2014, A1. Location in patent: Paragraph 00301