反应详情

A solution of 6-nitrobenzimidazole (2.0 g.) and methyl 4-bromomethyl-3-methoxybenzoate (B) (3.5 g.) in methyl ethyl ketone (61 ml.) was treated with potassium carbonate (1.9 g.) and then heated under reflux for 24 hours. The solvent was then evaporated. The residue was extracted with ethyl acetate and inorganic material removed by filtration. The filtrate was evaporated. The resultant residue was purified by flash chromatography on a 6×30 cm. silica gel column using 1:1 v/v hexane:ethyl acetate as the eluent to give methyl 3-methoxy-4-(6-nitrobenzimidazol-1-ylmethyl)benzoate (K) (1.07 g., 26%); NMR: 3.9 (s,3 H, OCH3), 4.0 (s,3 H, OCH3), 5.7 (s,2 H, NCH2), 7.4 (d, 1 H, Ar), 7.8 (d,1 H, H4 -benzimidazole), 8.1 (dd, 1 H, H5 -benzimidazole), 8.6 (br s,2 H2,7 -benzimidazole).

1. temperatureheated
2. temperatureunder reflux for 24 hours
3. customThe solvent was then evaporated
4. extractionThe residue was extracted with ethyl acetate and inorganic material
5. customremoved by filtration
6. customThe filtrate was evaporated
7. customThe resultant residue was purified by flash chromatography on a 6×30 cm