Indazole, oxathiadiazole, and thiadiazine derivatives from thiosemicarbazides

Abstract

4-Substituted thiosemicarbazides 1a–c reacted with 2,3-dicyano-5,6-dichloro-1,4-benzoquinone (DDQ, 2), 2,3,5,6-tetrachloro-1,4-benzoquinone (CHL-p, 6) and 2,3-dichloro-1,4-naphthoquinone (DCHNQ, 7) in ethyl acetate with admission of air and form the derivatives of 1,5,2,3-oxathiadiazole 8a–c, indazole 9a–c, 1,3,4-thiadiazine-6-one 10a–c, 1,3,4-thiadiazaphenanthren-9-one 11a–c, naphtho[1,2-e:4,3-è]bis1 Nogami, T., Yoshihara, K. and Nagakura, K. 1972. Bull. Chem. Soc. Jpn., 45: 122[Crossref] , [Google Scholar] 3 Belitskaya, L. D. and Kolesnikov, V. T. 1984. Zh. Org. Khim. (Eng. Translation), 20: 1753 [Google Scholar] 4 Foster, R., Kulevsky, N. and Wanigasekera, D. S. 1974. J. Chem. Soc., Perkin Trans., 1: 1318[Crossref] , [Google Scholar]thiadiazine 12 and dibenzo[b,i]thianthrene-5,7,12,14-tetraone 13. A rationale for the conversions observed is presented.