The Stoichiometry and Promoter Role of Chlorosulfuric and Fuming Sulfuric Acids for α-Halogenation of Aliphatic Acid

Article abstract of DOI:10.1246/bcsj.53.2417

The stoichiometry for the chlorosulfuric acid promoted α-halogenation and the role of fuming sulfuric acid instead of chlorosulfuric acid have been studied.In the α-bromination with molecular bromine, 1 mol of halogen afforded 2 mol of aliphatic α-bromo acid just as the α-iodination, but it is different from α-chlorination which affords only 1 mol of α-chloro acid.Fuming sulfuric acid instead of chlorosulfuric acid was found to be effective for α-bromination, but the yield was lower, while no α-iodination was observed with fuming sulfuric acid.