Syntheses And Spectral Characterizations Of 1, 2, 4-Triazolo[3, 4-b][1, 3, 4] Thiadiazoles And 1, 2, 4-Triazolo[3, 4-b][1, 3, 4] Thiadiazines

Triazolethiadiazole and triazolethiadiazine are condensed heterocyclic compounds with diverse biological activities, including antiparasitic, analgesic, antibacterial, antifungal, antivirus, anti-inflammatory, plant-growth regulating activities. In the recent report, some of these N-bridged heterocycles also can kill the tumour cell and the HIV. Substitutions at 3- and 6-positions of 1, 2, 4-triazolo[3, 4-b][l, 3, 4]thiadizoles and 1, 2, 4-triazolo[3, 4-b][l, 3, 4]thiadiazine ring systems may enchance their biological activity. In light of the above facts and with a view to obtain new biologically active agents, we synthesized a series of novel derivatives of 1, 2, 4-triazolo[3, 4-b][1, 3, 4]thiadizoles and 1, 2, 4-triazolo[3, 4-b][1, 3, 4]thiadiazine, elucidated their structures by elemental analysis, IR, NMR, MS techniques, and evaluated the plant growth regulating effects of some compounds.This thesis focuses on the syntheses and spectral characterization of some compounds of triazolethiadiazoles and triazolethiadiazines, which consists of the following parts:1 This part briefly introduced the structures of triazolethiadiazoles, triazolethiadiazines and related compounds, reviewed their synthetical methods and the reactive mechanisms.2 By the intermediates of 4-amino-5-mercapto-3-substitution-1, 2, 4-triazole, we synthesized several series compounds:1) Synthesized 3-benzyl-6-aryl-1, 2, 4-triazolo[3, 4-b] [1, 3, 4] thiadiazoles by 3-benzyl -4-amino-5-mercapto-1, 2, 4-triazole with aromatic acids in the presence of phosphorus oxychloride.2) Synthesized 3-(2-furanyl)-6-aryl-1, 2, 4-triazolo[3, 4-b][l, 3, 4] thiadiazoles by the usual methods, and found that these compounds had significant promoting effect on mung bean radicles.3) Synthesized 3-aryl-6-(1, 1' -biphenyl-4-yl)-7H-1, 2, 4-triazolo[3, 4-b][1, 3, 4] thiadiazines by means of 3-aryl-4-amino-5-mercapto-l, 2,4-triazoles with 2-bromo-4'-phenylacetophenone and investigated the plant growth regulating effects of those compounds.4) Synthesized 3-mercapto-5-aryl-4-arylideneamino-1, 2, 4-triazo-les.3 Prepared 3-(D-gluco-pentitol-1-yl)-1, 2, 4-triazole by Laila' method, and synthesized a series of new compounds of 6-aryl-3- (D-gluco-pentitol-l-yl)-7H-1, 2, 4-triazolo[3, 4-b][l, 3, 4]thiadiazines, which may improve their transportation in biological systems and play an especial role in the bodies due to the D-glucono residues.Synthesized 3-(glucurono-l-yl)-4-amino-5-mercapto-1, 2, 4-tri-azole and confirmed the structure by elemental analysis, IR, NMR, MS techniques, especialy by 1H-1H COSY, 13C-1H COSY, 13C-1H COLOC experiments.Synthesized three new dithiocarbohydrazones: 1, 5-bis (4-metho-xybenzaldehyde)dithiocarbohydrazone (1), 1, 5-bis (p-dimethyl aminobenzaldehyde) dithiocarbohydrazone (2), 1, 5-bis (2-fural-dehyde)dithiocarbohydrazone (3), and initially reported the 13C NMR data of the dithiocarbohydrazones. It was found that the partial 13C NMR signals of the title compounds presented small and broad, and were difficult to be detected as the result of different conformers or dimers formed in solution. The crystal structure of compound (1) was determined by X-ray single crystal diffraction.