Synthesis of 2,3-Dihydrobenzothiazol-1,1-dioxide and 2,3-Dihydro-1,4-benzothiazin-3-one Nitroderivatives from 2,4-Di- and 2,4,6-Trinitrobenzamides

Synthetic methods for the conversion of readily available 2,4-di- and 2,4,6-trinitrobenzamides to the previously unknown 2,3-dihydrobenzothiazol-1,1-dioxide, 2,3-dihydro-1,4-benzothiazin-3-one, and 2,3-dihydro-1,4-benzothiazin-3-one-1,1-dioxide nitroderivatives have been developed. The methods involve selective nucleophilic substitution of an ortho-nitrogroup in polynitrobenzamides by benzylthio or methoxycarbonylmethylthio group followed by oxidation of sulfur atom with hydrogen peroxide and transformation of the amido group to the methoxycarbonylamino group by reaction with diacetoxyiodobenzene in methanol under non-basic conditions. Cyclization of the resulting compounds under the action of diacetoxyiodobenzene or sodium methoxide leads to the 2,3-dihydrobenzothiazole and 2,3-dihydro-1,4-benzothiazin-3-one derivatives, respectively.

polynitrobenzamides - diacetoxyiodobenzene - 2,3-dihydrobenzothiazol-1,1-dioxides - 2,3-dihydro-1,4-benzothiazin-3-ones - 2,3-dihydro-1,4-benzothiazin-3-one-1,1-dioxides