反应详情

A solution of ethyl 4-amino-3-(benzylamino)benzoate (0.24 g, 0.89 mmol) and triethyl orthoformate (0.8 mL, 4.8 mmol) in ethanol (10 mL) and conc. HCl (7 drops) was heated to reflux for 24 hr. The solution was cooled to room temperature and concentrated, then diluted with ethyl acetate (100 mL) and washed with dilute aq. NaHCO3 (1×100 mL). Then organic layer was dried (MgSO4), filtered and then concentrated and the resulting residue was purified by flash chromatography (50% ethyl acetate/hexane then ethyl acetate) to provide 0.12 g (48%) of ethyl 3-benzyl-3H-benzo[d]imidazole-5-carboxylate as an off white solid.

1. temperatureto reflux for 24 hr
2. concentrationconcentrated
3. additiondiluted with ethyl acetate (100 mL)
4. washwashed with dilute aq. NaHCO3 (1×100 mL)
5. dry with materialThen organic layer was dried (MgSO4)
6. filtrationfiltered
7. concentrationconcentrated
8. customthe resulting residue was purified by flash chromatography (50% ethyl acetate/hexane