反应 #470448

反应方程式

NaHCO3

4-bromobenzene-1,2-diamine

trimethyl orthoformate

HCl

→

5-bromo-1H-benzo[d]imidazole

收率 100.0%

溶剂

water

DMF

反应条件

后处理

1. 1
   萃取extract with ethyl acetate (200 mL)
2. 2
   干燥The organic layer was dried over Na2SO4
3. 3
   浓缩concentrated

实验过程

To a solution of 4-bromobenzene-1,2-diamine (3 g, 16 mmol) in DMF (22 mL) were added trimethyl orthoformate (44 mL) and conc. HCl (1.5 mL) and the mixture was stirred at room temperature for 1 h. The mixture was diluted with water (200 mL) and adjusted to pH7 with saturated aqueous NaHCO3, extract with ethyl acetate (200 mL). The organic layer was dried over Na2SO4, concentrated to give 5-bromo-1H-benzo[d]imidazole (3.25 g, 100%) as an off-white solid. LCMS: 197 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ 7.33 (t, J=8.8 Hz, 1H), 7.55 (dd, J1=7.6 Hz, J=40 Hz, 1H), 7.79 (d, J=47.2 Hz, 1H), 8.26 (s, 1H), 12.61 (d, J=25.6 Hz, 1H).

来源