反应详情

A mixture of 5.1 g of 2,3-diamino-p-xylene, 200 mL of 88% formic acid and 20 mL of 12N hydrochloric acid is heated to reflux for 3 hours. The resulting mixture is cooled to room temperature and rotary evaporated. The residue is diluted with 100 mL of water, then basified with ammonium hydroxide (28-30%). The suspension is extracted with ethyl acetate (3×100 mL). The combined extracts are dried over magnesium sulfate and rotary evaporated to afford 4,7-dimethylbenzimidazole as a yellow solid.

1. temperatureis heated
2. temperatureto reflux for 3 hours
3. extractionThe suspension is extracted with ethyl acetate (3×100 mL)
4. dry with materialThe combined extracts are dried over magnesium sulfate
5. customrotary evaporated