Synthesis of thiadiazolobenzamide via cyclization of thioxothiourea and its Ni and Pd complexes

Abstract

In this study, the new compound, N-(3-methyl-4- oxo[1,3,4]thiadiazolo[2,3-c][1,2,4]triazin-7-yl) benzamide, could be obtained via two different reactions: 1) reaction of 4-amino-6-Methyl-3- (Methylsulfanyl)-1,2,4-triazin-5-one with benzoyl isothiocyanate under removal of methylmercaptane, 2) reaction of 4-amino-6-Methyl-3-thioxo- 1,2,4-triazin-5-one with benzoyl isothiocyanate under elimination of hydrogen sulfide. In both reactions a new bond between sulfur and nitrogen atoms was formed and a five-membered ring was created. The oxo thiadiazolo benzamide was characterized by IR-, 1HNMR- and 13CNMR spectroscopy as well as by Mass spectrometry. X-ray crystallography was used to shed light on the structure of this new compound. Two new complexes could be generated by coordination of oxo thiadiazolo benzamide to Pd(II) and Ni(II) ions. These complexes have been analyzed by IR-, 1HNMR- and 13CNMR spectroscopy, conductometry and Thermal gravimetry (TGA). Theoretical QM Calculation GIAO has also been applied to predict the structure of the Pd complex.