反应 #9062

反应方程式

(2-nitrophenyl)-terephthalamic acid methyl ester

acetic acid

→

methyl 4-(benzimidazol-2-yl)-benzoate

收率 86.0%

反应条件

后处理

1. 1
   温度at reflux for 1 h
2. 2
   温度The mixture was cooled
3. 3
   workup.STIRRINGstirred at room temperature for 2 h
4. 4
   浓缩concentrated under reduced pressure
5. 5
   其他The residue was partitioned between saturated sodium bicarbonate (10 mL) and ethyl acetate (10 mL)
6. 6
   其他the phases separated
7. 7
   洗涤the organic layer washed with saturated NaHCO3 (10 mL)
8. 8
   萃取The organic extract
9. 9
   干燥was dried (MgSO4)
10. 10
    过滤filtered
11. 11
    浓缩concentrated

实验过程

To a solution of (2-nitrophenyl)-terephthalamic acid methyl ester (0.23 g, 0.76 mmol) in glacial acetic acid (2.5 mL) was added iron powder (<5 μm mesh, 0.12 g, 2.1 mmol) and the mixture stirred at reflux for 1 h. The mixture was cooled, stirred at room temperature for 2 h and concentrated under reduced pressure. The residue was partitioned between saturated sodium bicarbonate (10 mL) and ethyl acetate (10 mL), the phases separated and the organic layer washed with saturated NaHCO3 (10 mL). The organic extract was dried (MgSO4), filtered and concentrated to give cyclized methyl 4-(benzimidazol-2-yl)-benzoate (0.163 g, 86%). 1H NMR (CDCl3) δ 3.96 (s, 3H), 7.32 (m, 2H), 7.53 (br, 1H), 7.84 (br, 1H), 8.17 (m, 4H), 9.65 (br, 1H (NH)).

来源