Synthesis
General procedure for the synthesis of methyl 1H-benzimidazole-2-carboxylate from methanol and 2-(trichloromethyl)-1H-benzo[d]imidazole: Sodium carbonate (Na2CO3, 0.64 g, 6.07 mmol) was added to a solution of 2-(trichloromethyl)-1H-benzo[d]imidazole (1.9 g, 6.07 mmol) in methanol (20 mL). The reaction mixture was heated to reflux for 14 h and subsequently cooled to room temperature. 1N hydrochloric acid (HCl) was added to the reaction solution and stirred for 0.5 hr. The reaction mixture was extracted with ethyl acetate (EA). The organic phase was washed with saturated brine, dried over anhydrous sodium sulfate (Na2SO4) and concentrated under reduced pressure to give methyl 1H-benzimidazole-2-carboxylate (0.89 g, yield not stated). Mass spectrometry (MS) analysis showed the molecular ion peak (M+1) to be 177, which was consistent with the theoretically calculated value (C9H8N2O2, 176).
References
[1] Patent: WO2011/143365, 2011, A1. Location in patent: Page/Page column 138
[2] Patent: WO2008/33739, 2008, A2. Location in patent: Page/Page column 31
