This invention relates to a process for removing color-forming and odorous impurities from alkanesulfonyl chlorides.
In the large scale production of alkanesulfonyl chlorides by oxidation of alkane thiols or dialkyl disulfides, it is desirable but extremely difficult to achieve complete oxidation of the odorous organosulfur impurities without overoxidation. Overoxidation with chlorine results in unwanted side-chain chlorination. On the other hand, underoxidation allows small amounts of the undesirable odorous oxidizable sulfur compounds to remain. These compounds may include the starting alkane thiols and dialkyl sulfides, as well as dialkyl sulfides, and alkyl alkanethiosulfonates. These and other impurities cause significant unpleasant odor and lead to the formation of color. Further, odor or color may develop when the alkanesulfonyl chloride or its aqueous dispersion is subsequently used as a reactant or solvent.