反应详情

温度

80 °C

2-Bromo-5-chlorobenzyl bromide prepared from 2-bromo-5-chlorotoluene (50 g), N-bromosuccinimide and N,N′-azobisisobutyronitrile, and ethyl 1-cyclohexyl-2-(4-hydroxyphenyl)benzimidazole-5-carboxylate (50 g) obtained in Example 3 were suspended in dimethylformamide (300 ml). Potassium carbonate (38 g) was added and the mixture was stirred for 1 hr at 80° C. with heating. The reaction mixture was allowed to cool and then added to a mixed solvent of water-ethyl acetate. The precipitated crystals were collected by filtration to give the title compound (50 g, yield 64%).

1. temperaturewith heating
2. temperatureto cool
3. filtrationThe precipitated crystals were collected by filtration