反应详情

2.52 g of N-bromosuccinimide and 0.42 of benzoyl peroxide were added to a solution of 4.07 g of diethyl 1-benzyl-2-methylimidazole-4,5-dicarboxylate [prepared as described in step (i) above] in 80 ml of carbon tetrachloride, and the mixture was irradiated by a 375 W tungsten lamp for 50 minutes, whilst stirring. At the end of this time, the reaction solution was washed with a 5% w/v aqueous solution of sodium thiosulfate and with a saturated aqueous solution of sodium hydrogencarbonate, in that order, after which it was concentrated by evaporation under reduced pressure. The resulting residue was purified by column chromatography through silica gel, using a 3:2 by volume mixture of hexane and ethyl acetate as the eluent, to give 3.81 g of the title compound as a syrup.

1. washAt the end of this time, the reaction solution was washed with a 5% w/v aqueous solution of sodium thiosulfate and with a saturated aqueous solution of sodium hydrogencarbonate, in that order
2. concentrationafter which it was concentrated by evaporation under reduced pressure
3. customThe resulting residue was purified by column chromatography through silica gel
4. additionby volume mixture of hexane and ethyl acetate as the eluent