反应详情

2.22 g of 5-benzyloxy-3-(1-tert-butoxycarbonyl-5-hydroxy-1H-indol-2-yl)-indazole-1-carboxylic acid tert-butyl ester and 7.8 g of cesium carbonate, in 22 ml of dibromoethane, are stirred at 80° C. (temperature of the oil bath) for 48 hours. The reaction mixture is filtered through sintered glass and the solid is rinsed with 20 ml of dichloromethane. The filtrate is concentrated under vacuum. The reaction crude is purified by flash chromatography on 160 g of silica. The eluent is 100% dichloromethane. 2 g of 5-benzyloxy-3-[5-(2-bromo-ethoxy)-1-tert-butoxycarbonyl-1H-indol-2-yl]indazole-1-carboxylic acid tert-butyl ester are isolated.

1. filtrationThe reaction mixture is filtered through sintered glass
2. washthe solid is rinsed with 20 ml of dichloromethane
3. concentrationThe filtrate is concentrated under vacuum
4. customThe reaction crude
5. customis purified by flash chromatography on 160 g of silica