Thermal decomposition of bismesitylsulphonyl- and bis-2,4-xylylsulphonyl-diazomethanes

Abstract

Thermal decomposition of bismesitylsulphonyldiazomethane provides 2,3-dihydro-5,7-dimethyl-2-mesitylsulphonylbenzo[b]thiophen 1,1-dioxide, the product of carbenic insertion into one of the ortho-methyl groups. An analogous product could not be isolated from bis-2,4-xylylsulphonyldiazomethane, whose decomposition was much more complex but provided small yields of 2,3-dihydro-5-methyl-2-(2,4-xylyl)benzo[b]thiophen 1,1-dioxide, 2,4-dimethylbenzoic acid, and di-2,4-xylyl disulphide. Small yields of the corresponding acid and disulphide were obtained from the mesityl diazo-compound and in both instances it is suggested that these arise from a Wolff-type rearrangement.