New methods of radiobromination. The sodium [77Br]bromide/tetrahalomethane/triphenylphosphine reagent system

The combination of sodium [77Br]bromide, tetrahalomethane and triphenylphosphine can be used to convert an alcohol to the corresponding 77Br-labeled alkyl bromide. Using carbon tetrachloride the no-carrier-added product is obtained, whereas use of carbon tetrabromide yields the carrier-added alkyl halide. The reaction is rapid (5-30 min) and proceeds under conditions of low temperature (0-50C), neutral pH, and without oxidizing agents. This new radiobromination procedure has been used to prepare [77Br]benzyl bromide and [77Br]16-bromohexadecanoic acid ethyl ester. (author)