反应详情

Mass spectrum (FAB, Pos): m/z 177 (M+ +1, as a free base). ##STR15## 2-Methylbenzimidazole-5-carboxylic acid hydrochloride, 6.6 g (32.5 mmols), was added to 200 ml of methanol and 5 ml of conc. hydrochloric acid was added to the mixture followed by heating to reflux for 8 hours. The solvent was distilled off under reduced pressure and 200 ml of water was added to the residue. After 1 N sodium hydroxide solution was added to the mixture to adjust pH to 9 to 10, the mixture was extracted with ethyl acetate. The ethyl acetate layer was dried over anhydrous magnesium sulfate and filtered. The solvent was distilled off to give 5.5 g (93.2%) of methyl 2-methyl-benzimidazole-5-carboxylate.

1. additionwas added to the mixture
2. temperatureby heating
3. temperatureto reflux for 8 hours
4. distillationThe solvent was distilled off under reduced pressure and 200 ml of water
5. additionwas added to the residue
6. additionAfter 1 N sodium hydroxide solution was added to the mixture
7. extractionthe mixture was extracted with ethyl acetate
8. dry with materialThe ethyl acetate layer was dried over anhydrous magnesium sulfate
9. filtrationfiltered
10. distillationThe solvent was distilled off