No abstract

Base-induced transformation of an equimolar mixture of 1-alkyl-1,3-dihydro-2,1-benzisothiazole 2,2-dioxides (benzosultams) and their 3,3-dichloro derivatives furnishes 1-alkyl-3-chloro-1,3-dihydro-2,1-benzisothiazole 2,2-dioxides which react with nitroarenes according to the vicarious nucleophilic substiution of hydrogen (VNS) mechanism giving 3-(nitroaryl)benzosultams.

Sulfuration O 0245Synthesis and Reactions of 3-Alkylsulfanyl-1,3-dihydro-2,1-benzisothiazole 2,2-Dioxides. -The course in reactions of benzosultams with sulfanylating agents depends on the structure of both starting materials. 3-Alkylbenzosultams (I) form with disulfides (II) the corresponding 3-sulfanyl derivatives, which via thermal extrusion of SO2 finally give 1-arylvinyl sulfides (IV). The reaction of benzosultams (V) or its pyrido analogue (VIII) with disulfides affords dithioacetal derivatives. By reaction of sultams (V) or (VIII) with ω-bromoalkyl thiocyanates, dihydrothiopyrans are formed via spiro compounds. Dihydrothiophene (XI) is directly obtained from the reaction with ω-chloro thiocyanate (X) without isolation of an analogous spiro intermediate. -(MODRZEJEWSKA, H.; WOJCIECHOWSKI*, K.; Tetrahedron 61 (2005) 37, 8848-8854; Inst. Org. Chem., Pol. Acad. Sci., PL-01-224 Warsaw, Pol.; Eng.) -Klein 50-048