Synthesis and properties of 5-amino-1,2,3-thiadiazole-4-carbothioamides

5-Amino-1,2,3-thiadiazole-4NR-carboxamides were reacted with P₄S₁₀, and 5-NR-amino-1,2,3-thiadiazole-4-carbonitriles with-H₂S. The reversible rearrangement of 5-amino-1,2,3-thiadiazole-4-NR-carbothioamides to 5-NR-amino-1,2,3-thiadiazole-4-carbothioamides was discovered.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1269–1273, September, 1988.     

2-Amino-5-methyl-1,3,4-thiadiazole and 2-amino-5-ethyl-1,3,4-thiadiazole

The structures of 2-amino-5-methyl-1,3,4-thia­diazo­le, C₃H₅N₃S, and 2-amino-5-ethyl-1,3,4-thia­diazo­le, C₄H₇N₃S, have been determined for comparison with unsubstituted 2-amino-1,3,4-thia­diazo­le. Despite their different space groups (P2₁/n and Pbca, respectively), the packing modes of the methyl and ethyl derivatives are similar, with comparable three-dimensional hydrogen-bonding associations. This is in contrast to the hydrogen-bonding network in 2-amino-1,3,4-thia­diazo­le, which is one-dimensional and has denser packing. It is shown that both packing forms are different polymorphs of a specific subunit of each array.     

Spontaneous ring transformation of a 5-azido-1,2,3-thiadiazole

The reaction of 4-carbethoxy-5-chloro-1,2,3-thiadiazole ($\text{1}$) with sodium azide results in the formation of ethyl α-thiatriazolyldiazoacetate ($\text{3}$) instead of the corresponding azide ($\text{2}$). Two plausible mechanisms for this new rearrangement are formulated.     

Mass-spectrometric study of isomeric 5-amino-1,2,3-thiadiazoles and 5-mercapto-1,2,3-triazoles

The behavior of the isomeric 5-amino-1,2,3-thiadiazoles and 5-mercapto-1,2,3-triazoles under electron impact was studied. It was shown that mass spectrometry can serve as a rapid and reliable method for the identification of these compounds. Key factors in the assignment of a compound to one or the other class are the peaks of the [M-N₂]⁺ ions, which are more intense in the case of the thiadiazoles, and the ions determined by the decomposition of the prototropic forms of the triazoles. The compositions of the ions were determined by the high-resolution mass spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 681–689, May, 1987.     

New 1,2,3-selenadiazole and 1,2,3-thiadiazole derivatives

New 1,2,3-thiadiazole and 1,2,3-selenadiazole derivatives, 14-23, were prepared from the ketones 1-5 via the corresponding semicarbazones or hydrazones 6-12. The Hurd-Mori and Lalezari methods were used, respectively, for the preparation of these 1,2,3-thiadiazole and 1,2,3-selenadiazole derivatives. The intermediate 13 was also trapped, separated and fully characterized. These derivatives are important for photocrosslinking processes and due to their potential biological activity.     

Isomere 4-Phenyl-5-amino-1,2,3-triazole

Ohne Zusammenfassung     

Synthesis,Crystal Structure and Biological Activity of N-tert-butyl-N-(4-methyl-1,2,3-thiadiazole)-5-yl-N’-(4-methyl-1,2,3-thiadiazole)-5-formyl-N’-3,5-dichloropyridin-2-yl-diacylhydrazine

The title compound N-tert-butyl-N-(4-methyl-1,2,3-thiadiazole)-5-yl-N'-(4-me-thyl-1,2,3-thiadiazole)-5-formyl-N'-3,5-dichloropyrid-2-yl-diacylhydrazines (C18H17Cl2N7O3S2, Mr = 514.41) has been synthesized by the reaction of N-tert-butyl-N'-3,6-dichloropyridine-2-formyl hydrazine with 4-methyl-1,2,3-thiadiazole-5-carbonyl chloride and triethylamine, and its structure was characterized by 1H NMR, HR MS, and single-crystal X-ray diffraction. The crystal of the title compound belongs to monoclinic, space group C2/c with a = 27.726(8), b = 11.045(3), c = 14.507(4), β = 96.758(4)°, Z = 8, V = 4412(2) 3, Dc = 1.549 g/cm3, μ = 0.521 mm-1, F(000) = 2112, R = 0.0405 and wR = 0.1153. X-ray analysis indicates that all rings are non-planar in this molecule. The bioassay results indicate that both the title compound and the positive control RH-5992 have weak fungicide activities, while the title compound has good insecticidal activity against Plutella xylostella L. and no insecticidal activity against Culex pipiens pallens.     

Rearrangement of 5-amino-1,2,3-thiadiazole-4-carbothioamides

Conclusions A new rearrangement in the series of 5-amino-1,2,3-thiadiazole-4-carbothioamides was observed.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1126–1128, May, 1988.     

Synthesis of 5-dialkylamino-1,2,3-triazoles and 2-amino-1-azirines from tertiary amides

The reaction of sodium azide with β-monosubstituted-α-chloroenamines (generated from tertiary amides) yields either 5-dialkylamino-1,2,3-triazoles or 2-amino-1-azirines according to the basicity of the amine substituent.     

Disperse dyes derived from 2-amino-5-mercapto-1,3,4-thiadiazole

Some novel heterocyclic monoazo dyes based on 2-amino-5-mercapto-1,3,4-thiadizole have been synthesized by coupling with various N-phenylacrylamide derivatives. The dyeing performance of these dyes was assessed on polyester fabrics. IR and visible spectra of the dyes were examined. The percentage dye bath exhaustion, fixation, and various fastness properties of the dyes were also determined. These dyes were found to give brownish-orange to reddish-pink shades on dyeing with good depth, levelness, and brightness on fabric. The dyed fabric showed a good to excellent fastness to washing, rubbing, perspiration, and sublimation.     

Synthesis and biological evaluation of novel 1,2,4-triazole containing 1,2,3-thiadiazole derivatives

A series of novel 1,2,4-triazoles containing 1,2,3-thiadiazole derivatives were designed and synthesized. Their structures were confirmed by melting points, IR, 1H NMR, and elemental analysis and ESI-MS or HRMS. Preliminary bioassays indicated that these compounds exhibited very good insecticidal activity against Aphis laburni at 100 μg/mL, with mortality no less than 95%. Compounds 6a, 6c, 6f, 61 showed higher curative activity against TMV and compound 6h showed a higher induction effects against TMV in vivo at 100 μg/mL. Collectively, our data demonstrate a new strategy for control of insects and viruses.     

Die thermische wolff-umlagerung der 1,2,3-thiadiazole

Thermal nitrogen elimination of 1,2,3-thiadiazoles leads to primary fragments, which rearrange to thioketenes. In the presence of high boiling alcohols like diglycol, the corresponding esters can be isolated in good yields. Benzo-1,2,3-thiadiazole, which does not rearrange, is an exception, because of the integrity of the aromatic nucleus.