Synthesis and Mass Spectral Studies of Some (E)- and (Z)-1-Alkylthio - and 1-Alkylsulphonyl-2-P-Tolylsulphonylstilbenes

Abstract

A number of (E)- and (Z)-1-alkylthio-2-p-tolylsulphonylstilbenes (3a–i and 5a–i) were synthesized by the nucleophilic displacement of halogens with sodium salts of various alkanethiols on (E)-1-chloro-2-p-tolylsulphonylstilbene (1) and (Z)-1-bromo-2-p-tolylsulphonylstilbene (2) respectively. Oxidation of these (E) - and (Z)-1-alkylthio-2-p-tolylsulphonyl gave the corresponding (E)- and (Z)-1-alkylsulphonyl-2-p-tolylsulphonylstilbenes (4a–i and 6a–i) respectively. Mass spectral data of all the synthesized compounds were examined. Smiles-type rearrangement observed in (E)-and (Z)- sulphide-sulphones (3a–i and 5a–i) was absent in (E)- and (Z)-disulphones (4a–i and 6a–i). Loss of sulphur dioxide and sulphonyl-sulphinate rearrangement with vinyl migration was noticed in all the synthesized compounds. McLafferty-type rearrangement was observed only in (E)- sulphide-sulphones and (E)- disulphones but not in the corresponding (Z)-isomers.