Ethyl5-acetoxy-6-bromo-2-(bromomethyl)-1-methylindole-3-.

40945-79-7

110543-98-1

General procedure for the synthesis of ethyl 1-methyl-2-(bromomethyl)-5-acetoxy-6-bromoindole-3-carboxylate from ethyl 5-acetoxy-1,2-dimethylindole-3-carboxylate: 137.6 g (0.45 mol) of ethyl 5-acetoxy-1,2-dimethylindole-3-carboxylate was dissolved in 1000 mL of chloroform with stirring until completely dissolved. A catalytic amount of benzoyl peroxide was added and heated to reflux. 64.0 mL (200 g, 1.25 mol) of liquid bromine was added slowly dropwise and the reaction was continued at reflux for 3 hours after completion of the dropwise addition. Upon completion of the reaction, the reaction mixture was cooled to room temperature and a solid was precipitated. The solid was washed with a small amount of methanol and dried to give 184.0 g of ethyl 1-methyl-2-(bromomethyl)-5-acetoxy-6-bromoindole-3-carboxylate in 85.0% yield.