Thallium(I) carboxylate modification of the hunsdiecker reaction

Abstract

Treatment of a Thallium(I) carboxylate with 1 molar equivalent of bromine gives the corresponding thallium(III) carboxylate dibromide. High yields of primary alkyl bromides are obtained if the thallium(III) carboxylate dibromide is treated with 0.5 mol equiv. of bromine in refluxing carbon tetrachloride. Pyrolysis of the thallium(III) derivative in the absence of added bromine gives a low yield of the corresponding alkyl bromide. The use of Thallium(I) carboxylates for the preparation of alkyl bromides in high yields is limited to the salts of primary carboxylic acids. A simple procedure for the preparation of alkyl bromides from carboxylic acids using Thallium(I) carbonate has been developed.