Title:Synthesis of Novel Fused Heterocyclic Compounds from 7-amino-[1,2,4]triazino[3,4- b][1,3,4]thiadiazine-8-carbonitrile
VOLUME: 9 ISSUE: 4
Author(s):Hosam A. Saad
Affiliation:Department of Chemistry, Faculty of Science, Taif Univeristy, Taif, KSA.
Keywords:1, 3, 4-thiadiazin-4-one, carbamodithioic acid, cyanamide, bromomalononitrile, thiadiazine-9-carbonitrile, triazino[3, 4-
b][1, 3, 4]thiadiazine, carbonitrile, guanidine.
Abstract:A one-pot synthesis of 7-amino-4-oxo-3-(2-(2-thienyl)vinyl)-4,8-dihydro-[1,2,4]triazino[3,4-b][1,3,4]thiadiazine-8-
carbonitrile (2) via the reaction of 4-amino-3-sulfanyl-6-[2-(2-thienyl)vinyl]-1,2,4-triazin-5(4H)-one (1) with bromomalononitrile is described.
The formation of the new fused heterobicyclic and heterotricyclic nitrogen systems ([1,2,4]triazino[3,4-b][1,3,4]thiadiazin-7-
yl)guanidine 3, pyrimido[4,5-e][1,2,4]triazino[3,4-b][1,3,4]thiadiazin-4-one 5, [1,2,4]triazino[3,4-b][1,3,4]thiadiazin-7-ylcarbamodithioic
acid 6, pyrimido[4,5-e][1,2,4]triazino[3,4-b][1,3,4]thiadiazin-4-one 8, [1,2,4]triazino[3,4-b][1,3,4]thiadiazin-7-ylformimidate 9,
pyrido[2,3-e][1,2,4]triazino[3,4-b][1,3,4]thiadiazine-9-carbonitrile 11, (pyrimido[4,5-e][1,2,4]triazino[3,4-b][1,3,4]thiadiazin-8-yl) acetonitrile
12 and pyrimido[4,5-e][1,2,4]triazino[3,4-b][1,3,4]thiadiazine-4,10(10aH)-dione 13 was achieved by treating 2 with cyanamide,
urea, thiourea, CS2 and ethanolic ethoxide, formamide, triethyl orthoformate, malononitrile, ethyl cyanoacetate and chloroacetyl chloride,
respectively. Additionally, the 8-thiourea and 8-acetamide derivatives 16a,b, 18 and 19 were synthesized by reacting 2 with various isothiocyanate
derivatives and acetic anhydride. The structures of all synthesized compounds were deduced by elemental analysis, mass
spectrometry and analysis of their spectral data (IR, 1H NMR, 13C NMR).
