sulfonyl chloride

Aromatic sulfonic acids and sulfonyl chlorides can be prepared by sulfonation of benzene derivatives with fuming sulfuric acid and chlorosulfonic acid, ClSO₃H, respectively, while aliphatic sulfonic acids are prepared by vigorous oxidation of thiols or by reaction of amine sulfur trioxide complexes (e.g., Me₃NSO₃) with organolithium compounds. Trifluoromethanesulfonic acid…

…the sulfonic acid chlorides, called sulfonyl chlorides.