反应详情

A mixture of 2,3-diamino-6-nitrotoluene (0.945 g, 5.65 mmol), conc. hydrochloric acid (5 mL) and glacial acetic acid (30 mL) is heated to reflux for 2 hours. The mixture is cooled to room temperature, then poured in a mixture of crushed ice (100 mL) and ammonium hydroxide (100 mL) and extracted with 20% methanol in chloroform (2×400 mL). The combined extracts are dried over potassium carbonate and rotary evaporated to afford 2,4-dimethyl-5-nitrobenzimidazole as a brown solid. The product is used in the following step without further purification.

1. temperatureis heated
2. temperatureto reflux for 2 hours
3. extractionextracted with 20% methanol in chloroform (2×400 mL)
4. dry with materialThe combined extracts are dried over potassium carbonate
5. customrotary evaporated