Reactions of sodium borohydride. IV. Reduction of aromatic sulfonyl chlorides with sodium borohydride.

Abstract

Aromatic sulfonyl chlorides were reduced with sodium borohydride in tetrahydrofuran at 0 C to the corresponding sulfinic acids in good yields. Further reduction proceeded when the reaction was carried out under reflux in tetrahydrofuran to give disulfide and thiophenol derivatives via sulfinic acid. Furthermore, sulfonamides were reduced with sodium borohydride by heating directly to give sulfide, disulfide and thiophenol derivatives, and diphenyl sulfone was reduced under similar conditions to give thiophenol and biphenyl