1. Methyl 1-methyl-1H-benzimidazole-2-carboxylate (190 mg, 1.0 mmol) and NaOH (80 mg, 2.0 mmol) in a mixture of MeOH/H2O (1:1, 20 mL) were stirred and reacted for 1 hr at 50°C. The reaction was carried out with the help of a stirring device.
2. Upon completion of the reaction, the mixture was concentrated and then diluted with 15 mL of water.
3. The pH of the diluted solution was adjusted to 2 with concentrated hydrochloric acid, at which time a precipitate was formed. 4.
4. The precipitate was collected by filtration, washed with water and dried to give 1-methyl-1H-benzimidazole-2-carboxylic acid (176 mg, 1.0 mmol, 100% yield).
5. The product was analyzed by ESI-MS and the (M + 1) peak was 177, which corresponded to the calculated value of C9H8N2O2 (176).
