反应详情

To a cold (ice bath) solution of 4,7-dimethylbenzimidazole (1 g) in concentrated sulfuric acid (8 mL) is added dropwise concentrated nitric acid (0.37 mL), over 50 minutes. The mixture is stirred an additional 30 minutes in the ice bath, then poured into a mixture of crushed ice (30 mL) and ammonium hydroxide (30 mL). The resulting mixture is extracted with ethyl acetate. The extract is dried over MgSO4 and rotary evaporated to afford 4,7-dimethyl-5-nitrobenzimidazole as a dark tan solid.

1. extractionThe resulting mixture is extracted with ethyl acetate
2. dry with materialThe extract is dried over MgSO4
3. customrotary evaporated