Sulfuryl Chloride Promoted gem-Dichlorination–Dehydrochlorination in Alkyl Benzothiazinylacetates: Synthesis of the Skeleton of Trichochrome Pigments

Abstract

Chemo- and stereoselective total synthesis of the basic trichochrome skeleton is described starting from o-aminothiophenol and maleic anhydride in very good overall yield. The process involves the synthesis of the corresponding 1,4-benzothiazin-2-ylacetates followed by their sulfuryl chloride induced dihalogenation–dehydrohalogenation and a second condensation with o-aminothiophenol as key steps.

Key words

o-aminothiophenol - maleic anhydride - halogenation - condensations - trichochrome framework

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