Fused polycyclic nitrogen-containing heterocycles: IX. Synthesis and molecular structure of methyl 3-(2-R-5-phenylthiazol-4-yl)-7-phenyl-7<Emphasis Type="Italic">H</Emphasis>-[1,2,4]triazolo-[3,4-<Emphasis Type="Italic">b</Emphasis>][1,3,4]thiadiazine-6-carboxylates

4-Amino-3-(2-R-5-phenylthiazol-4-yl)-1,2,4-triazole-5-thiones react with methyl 3-chloro-2-oxo-3-phenylpropionate to give methyl 3-(2-R-5-phenylthiazol-4-yl)-7-phenyl-7H-1,2,4]triazolo3,4-b]1,3,4]thiadiazine-6-carboxylates. According to the X-ray diffraction data, the thiazole ring in the products is planar, while the thiadiazine ring has a distorted unsymmetrical boat conformation. Depending on the substituent in the thiazole ring, methyl 3-(2-R-5-phenylthiazol-4-yl)-7-phenyl-7H-1,2,4]triazolo3,4-b]1,3,4]thiadiazine-6-carboxylates in crystal give rise to different supramolecular structures, lamellar and cylindrical.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 9, 2004, pp. 1358–1365.Original Russian Text Copyright © 2004 by Mamedov, Mustakimova, Gubaidullin, Litvinov, Levin.