Preparation and Spectral Characterization of 3-Benzyl-6-aryl-1,2,4-triazolo[3,4-b][1,3,4]thiadiazoles

3-Benzyl-4-amino-5-mercapto-1,2,4-triazole reacted with aromatic acids in the presence of phosphorus oxychloride, yielding a series of new compounds, i.e., 3-benzyl-6-aryl-1,2,4-triazolo[3,4-b][1,3,4]thiadiazoles, each of which has an active methylene at 3-position. The structures of all the title compounds were confirmed by elementary analysis, IR, 1H NMR and 13C NMR spectra.     

Efficient Synthesis of Fluorinated [1,2,4]Triazolo[3,4-b][1,3,4]thiadiazoles

Russian Journal of Organic Chemistry - An efficient synthesis of fluorinated [1,2,4]triazolo[3,4-b][1,3,4]thiadiazole derivatives has been achieved by cyclocondensation of 5-substituted...     

均三唑并噻二唑衍生物的微波合成

在无溶剂无催化剂微波辐射下,羧酸与1,3-二氨基硫脲快速反应高产率得到了3-取代基-4-氨基-5-巯基-1,2,4-三唑,该化合物与苯甲酰氯在无溶剂无催化剂微波促进下可以方便地制备化合物3-取代基-6-苯基-1,2,4-三唑[3,4-b][1,3,4]噻二唑。该方法具有反应时间短、环境友好、易于纯化及高产率的优点。产物结构经IR和1HNMR谱进行了表征。     

Crystal structure of 6-ferrocenyl-3-phenyl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole

A new compound of 6-ferrocenyl-3-phenyl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole is synthesized and its single crystal structure is determined by X-ray diffraction method. The compound belongs to the monoclinic P2₁/c space group with cell parameters: a = 10.5523(12) Å, b = 13.8414(16) Å, c = 11.4303(13) Å, V = 1603.5(3) ų.     

Novel [1,2,4]triazolo[3,4-b][1,3,4]thiadiazine and [1,2,4]triazolo[3,4-b][1,3,4]thiadiazepine Derivatives: Synthesis,Anti-Viral In Vitro Study and Target Validation Activity

This study of the interaction system of binucleophilic 3-substituted 4-amino-4H-1,2,4-triazole-5-thiols and 3-phenyl-2-propynal made it possible to develop a new approach to synthesis of such isomeric classes as 7-benzylidene-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine and 8-phenyl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazepine. Among the 20 compounds studied in vitro against influenza A/Puerto Rico/8/34 (H1N1) virus, half of them demonstrated selectivity index (SI) of 10 or higher and one of them (4-((3-phenylprop-2-yn-1-yl)amino)-4H-1,2,4-triazole-3-thiol) possessed the highest (SI > 300). Docking results and values showed that the preferred interactant for our ligands was M2 proton channel of the influenza A virus. Protein-ligand interactions modeling showed that the aliphatic moiety of ligands could negatively regulate target activity level.     

Anodic formation of 3,6-diaryl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles and 2(3-aryl-5-methyl-1H-[1,2,4]triazol-1-yl)-5-aryl-1,3,4-thiadiazoles

3,6-Disubstituted 1,2,4-triazolo[3,4-b][1,3,4]thiadiazoles together with the unknown systems 2-(3-aryl-5-methyl-1H-[1,2,4]triazol-1-yl)-5-aryl-1,3,4-thiadiazoles were obtained by anodic oxidation, under aprotic conditions, of aryl aldehyde N-(5-aryl-1,3,4-thiadiazol-2-yl) hydrazones. Mechanistic proposals are given.     

Synthesis and opening of the thiadiazine ring in 6,7-dihydro-5H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines

A reaction of 3-benzylthiotriazole-4-amines with aromatic aldehydes leads to the formation of 6,7-dihydro-5H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines. A dihydrothiadiazine ring opening along the N-N bond occurs by the action of strong bases. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1249–1252, June, 2008.     

Synthesis and Crystal Structure of 3-Benzyl-6-trichloromethyl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole

The title compound 3-benzyl-6-trichloromethyl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole I （C11HTC13N4S, Mr = 333.62） has been synthesized, and its structure was determined by elemental analyses, IR, ^1H NMR, ^13C NMR, and X-ray diffractions. The crystal is of triclinic, space group P1^-, with a = 5.898（3）, b = 10.510（4）, c = 11.580（5） A, α = 74.936（7）, β= 75.476（7）, γ = 79.647（7）°, V= 665.9（5）/A^3, F（000） = 336, Z= 2, Dc = 1.664 g/cm^3, 2 = 0.71073A, p = 0.834 mm^-1, the final R = 0.0605 and wR = 0.0900. The secondary bonding interactions （SBIs） S…N and π-π stacking interactions are found in the crystal structure and they link the molecules into a three-dimensional network.     

Destructive hydrazinolysis of [1,2,4]triazolo[3,4-b]-[1,3,4] thiadiazole derivatives

The hydrazinolysis of 2-mercapto[1,2,4]triazolino[3,4-b][1,3,4]triadiazole-5-thione and its S-methyl and disulfonyl derivatives leads to opening of the thiadiazole ring during attack by the nucleophile on the bridge carbon atom. A study of the structures of the reaction products and calculations by the Hückel MO and Pariser-Parr-Pople (PPP) method makes it possible to draw a conclusion regarding the mechanism of the hydrazinolysis.     

C–H Arylation using acyl thiourea ligands: Applications in the synthesis of 3,6-diaryl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles

Synthesis of a series of new 3,6-diaryl-[1,2,4]triazolo[3,4-b] [1,3,4]thiadiazoles(5a–o) was achieved by phophine free, C–H arylative cross-coupling of 6-aryl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles(4a–o)with suitably substituted iodoanilines using 1-(2-naphthoyl)-3-(4-bromophenyl)thiourea as a ligand.The requisite triazolothiadiazoles(4a–o) were obtained by the condensation of 4-amino-1,2,4-triazole-3-thiol(3) with suitably substituted aromatic acids in the presence of phosphoryl chloride.     

Synthesis of 6-aryl-3-cinchophenyl-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles

In recent years, fused heterocycles have been found to possess many unique properties in synthesis and pharmacology. Especially, 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles derivatives have been attracting much attention of chemists and pharmacologists because of their broad-spectrum biological activities such as antibacterial¹, hypotensive and CNS depressant² activities. We have prepared some 3,6-substituted 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles and found that these compounds exhibited antimacrobial, insecticidal and promote plant growth.^3-5 Cinchophen had been used widely as medicine in clinic,but has been obsolete in recent years due to its by-effect. In order to seek for other uses of cinchophen, as a continuation of our preceeding studies, we used cinchophen as the starting material to synthesize ten new 6-aryl-3-cinchophenyl-l,2,4-triazolo[3,4-b]-l,3,4-thiadiazoles 5a-j. Compound 1 was prepared by the reaction of cinchophen and ethanol in the presence of sulfuric acid. 1 then reacted with hydrazine hydrate in absolute ethanol to give 2 which yielded 3 on treatment with CS₂ and KOH. On refluxing of 3 with excess hydrazine hydrate, 4 was obtained. 4 reacted with various substituted benzoic acids in the presence of POCl₃ to afifort 5a-j.     

6-Arylamino-3-methyl-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines: Novel N-Arylamidine Structures

We propose a method for obtaining derivatives of 7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine by alkylation of 4-amino-5-methyl-4H-1,2,4-triazole-3-thiol by substituted -chloroacetanilides, followed by cyclization of the intermediate by phosphorus oxychloride.     

Preparation and Electrochemical Properties of 3-Phenyl-6-aryl-1,2,4-triazolo[3,4-b][1,3,4]-thiadiazoles

Since Tang firstly reported the electroluminescence of 8-hydroxyquinoline aluminium, much attention has been paid to the organic compound as electro-luminescent material. Especially, electron transport materials play an important role in organic light-emitting diode (OLED).2-(4-Biphenyl)-5-(t-butylphenyl)-1, 3,4-oxadiazole (PBD), as a kind of popular electron injection/transport materials, can improve remarkably the     

Synthesis under microwave irradiation of [1,2,4]triazolo[3,4-b] [1,3,4]thiadiazoles and other diazoles bearing indole moieties and their antimicrobial evaluation

Microwave-assisted synthesis of some novel compounds, namely, 3-(2-methyl-1H-indol-3-yl)-6-aryl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles 5a,b was accomplished via bromination of 2-methyl-3-[4-(arylideneamino)-5-mercapto-4H-[1,2,4]triazol-3-yl]-1H-indoles 3a,b. Also, new [1,3,4]thiadiazoles 12a,b, [1,2,4]triazoles 15a,b and [1,3,4]oxadiazoles 19a,b, with indole moieties, were prepared by cyclization of 1-[(2-methyl-1H-indole)-3-carbonyl]thiosemicarbazides 8a,b under microwave irradiation using different reaction conditions. Moreover, reaction of acid hydrazide 7 with ethyl 2-(N-phenylhydrazono)-3-oxobutanoate (20) gave the respective phenylhydrazonopyrazole derivative 21 under the reaction conditions employed. The structures of the synthesized compounds were assigned based on elemental analyses and spectral data (IR, (1)H-NMR, (13)C-NMR, MS). The antifungal and antibacterial activities of the new products were also evaluated.     

The efficient synthesis of 3-[6-(substituted)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazol-3-yl]-1H-indazole

This study presents an efficient synthesis of 3-[6-(substituted-phenyl)-[1,2,4]triazolo[3,4-b][1,3,4] thiadiazol-3-yl]-1H-indazole via dehydrative condensation with cyclization of 4-amino-5-(1H-indazol-3-yl)-4H-[1,2,4]triazole-3-thiol and fluorinated or nonfluorinated carboxylic acids in presence of phosphorous oxychloride. The multistep reaction pathway proceeds through different compounds. Present synthesis has the advantages of easily accessible starting materials, convenient synthesis, simple reaction condition, wider substrate scope, and higher yield (75% to 90% isolated).     

Preparation and Electrochemical Properties of 3-Phenyl-6-aryl-1,2,4-triazolo[3,4-b][1,3,4]-thiadiazoles

Introduction Since Tang[1] firstly reported the electroluminescence of 8-hydroxyquinoline aluminium, much attention has been paid to the organic compound as electro-luminescent material. Especially, electron transport materials play an important role in organic light-emitting diode(OLED). 2-(4-Biphenyl)-5-(t-butylphenyl)-1,3,4-oxadiazole(PBD), as a kind of popular electron injection/transport materials, can improve remarkably the injection balance of electrons and holes. As a result, it can amend the properties of OLED[2,3].     

5,6-2H-1,2,4-三唑[3,4-b][1,3,4]噻二嗪衍生物的合成及抗癌活性测定

取代苯甲醛与4-氨基-5-(3,4,5-三甲氧基苯基)-1,2,4-三唑-3-硫酮(2)缩合生成5-(3,4,5-三甲氧基苯基)-4-取代苯基亚胺基-1,2,4-三唑-3-硫酮(3),再烷基加成化为新型5,6-2H-1,2,4-三唑[3,4-b][1,3,4]噻二嗪衍生物4.化合物结构经1HNMR 13C NMR,IR以及元素分析确认.采用噻唑兰(MTT)比色法进行化合物抑制人体前列腺癌细胞(PC3)体外活性测试,结果表明所合成的化合物具有不同程度的抑制PC3活性,其中化合物4a在10μmol·L-1浓度下对PC3的抑制率为75.9%.     

Stereospecific synthesis of 6,7-dihydro-5H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazines

The reaction of 3-mercapto-4-arylideneamino-1,2,4-triazoles 2b-d , 3a-d with ethyl bromoacetate and/or phenacyl bromide in hot DMF and triethylamine affords the stereochemically pure 7-acyl-6-aryl-6,7-dihydro-5H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazines 4b-d , 5a-d , 6b , d in which the consecutive hydrogen atoms N(5)H-C(6)H-C(7)H are cis to each other. This stereochemistry was determined by ¹H NMR spectroscopy and confirmed by comparison with the spectrum of 3,6-diphenyl-6,7-dihydro-5H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazine 10 . The latter was prepared by NaBH₄ reduction of 3,6-diphenyl-5H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazine 9 . The reported reactions offer two interesting stereospecific syntheses of the condensed heterocyclic compounds.