Preparation of alkanesulfonyl halides and alkanesulfonic acids

A continuous method is provided for preparing alkanesulfonyl halides, particularly chlorides and alkanesulfonic acids in high yields without the formation of undesirable side-products, and without the net production of hydrogen chloride as a by-product. The method involves the continuous electrolysis of an alkanethiol (RSH) or dialkyl disulfide (RSSR min ) in an aqueous hydrochloric acid-containing solution, continuously removing the electrolyzed product mixture from the electrolysis zone, and recovering the alkanesulfonyl chloride (RSO2Cl) or alkanesulfonic acid (RSO3H) product from the mixture. The alkyl groups in the dialkyl disulfide (R and R min ) may be straight or branched chain, substituted or unsubstituted, have 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms, and may be different, but are preferably the same. The aqueous hydrochloric acid-containing medium and any unreacted sulphur compounds may be recycled through the electrolysis chamber.