Synthesis of 2-aryl-4,6-dinitrobenzo[d]isothiazolium from 2,4,6-trinitrotoluene

A method for the synthesis of previously unknown 2-aryl-4,6-dinitrobenzo[d]isothiazolium has been developed based on the replacement of ortho-NO₂ in N-(2,4,6-trinitrobenzylidene)anilines by treatment with PhCH₂SH/K₂CO₃ followed by conversion of the resulting N-(2-benzylthio-4,6-dinitrobenzylidene)anilines with SO₂C1₂.