Silver Salt and Derivatives of 5‐Azido‐1H‐1, 2, 4‐triazole‐3‐­carbonitrile

This study features the preparation of three new energetic C‐azido‐1, 2, 4‐triazoles, with the anion of one being a new binary C–N compound. 5‐Azido‐1H‐1, 2, 4‐triazole‐3‐carbonitrile ( 1 ) was prepared from 5‐amino‐1H‐1, 2, 4‐triazole‐3‐carbonitrile and further derivatized to 5‐azido‐1H‐1, 2, 4‐triazole‐3‐carbohydroximoyl chloride ( 5 ) with 3‐azido‐1H‐1, 2, 4‐triazole‐5‐carboxamidoxime ( 3 ) as an intermediate. The ability of 1 and 3 for salt formation was shown with the respective silver salts 2 and 4 . All compounds were well characterized by various means, including IR and multinuclear NMR spectroscopy, mass spectrometry, and DSC. The molecular structures of 1 , 3 , and 5 in the solid state were determined by single‐crystal X‐ray diffraction. The sensitivities towards various outer stimuli (impact, friction, electrostatic discharge) were determined according to BAM standards. The silver salts were additionally tested for their potential as primary explosives.     

Synthesis of Some Novel 3,6‐Bis(1,2,3‐triazolyl)‐s‐triazolo[3,4‐b]‐1,3,4‐thiadiazole Derivatives

The cyclization of 1‐amino‐2‐mercapto‐5‐[1‐(4‐ethoxyphenyl)‐5‐methyl‐1,2,3‐triazol‐4‐yl]‐1,3,4‐triazole which was synthesized from p‐ethoxyaniline with various triazole acid in absolute phosphorus oxychloride yields 3,6‐bis(1,2,3‐triazolyl)‐s‐triazolo[3,4‐b]‐1,3,4‐thiadiazole derivatives 9a?j , and their structures are established by MS, IR, CHN and ¹H NMR spectral data.     

Study of the oxidation of some catechols in the presence of 4‐amino‐3‐thio‐1,2,4‐triazole by digital simulation of cyclic voltammograms

Electrochemical oxidation of catechol and its derivatives ( 1a–d ) has been studied in the presence of 4‐amino‐3‐thio‐1,2,4‐triazole ( 3 ) at various pHs. Some electrochemical techniques such as cyclic voltammetry using the diagnostic criteria derived by Nicholson and Shain for various electrode mechanisms and controlled‐potential coulometry were used. Results indicate the participation of catechols ( 1a–d ) with 3 in an intramolecular cyclization reaction to form the corresponding 1,2,4‐triazino[5,4‐b]‐1,3,4‐thiadiazine derivatives. In various scan rates, based on an electron transfer–chemical reaction–electron transfer–chemical reaction mechanism, the observed homogeneous rate constants (k_obs) for Michael addition reaction were estimated by comparing the experimental cyclic voltammetric responses with the digital simulated results. The oxidation reaction mechanism of catechols ( 1a–d ) in the presence of 4‐amino‐3‐thio‐1,2,4‐triazole ( 3 ) was also studied. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 39: 340–345, 2007     

3-氨基-1H-1,2,4三唑类席夫碱的合成和生物活性

以醋酸为催化剂,用3-氨基-1H-1, 2, 4-三唑与取代苯甲醛反应合成了8个3-氨基-1H-1, 2, 4-三唑类席夫碱,化合物结构经1H NMR,IR和元素分析证实,并对其进行了生物活性测试,初步生物活性结果表明此类化合物具有良好的杀菌活性。     

Synthesis and crystal structure of novel schiff bases derived from 3‐(2‐ethoxyphenyl)‐4‐amino‐5‐mercapto‐4H‐1,2,4‐triazole

A series of novel 4‐(arylmethylidene)amino‐5‐(2‐ethoxyphenyl)‐3‐mercapto‐4H‐1,2,4‐triazoles ( 2a‐f ) were easily synthesized in high yields by means of the reactions of 3‐(2‐ethoxyphenyl)‐4‐amino‐5‐mercapto‐4H‐1,2,4‐triazole ( 1 ) with various aromatic aldehydes. The compound, 4‐(4‐methylbenzylidene)‐amino‐5‐(2‐ethoxyphenyl)‐3‐mercapto‐4H‐1,2,4‐triazole was investigated with X‐ray crystallography.     

Synthesis and Antibacterial Activity of s‐Triazoles,s‐Triazolo[3,4‐b]‐1,3,4‐thiadiazines and s‐Triazolo[3,4‐b]‐1,3,4‐thiadiazoles of 5‐Methylisoxazole

The condensation of 4‐amino‐5‐mercapto‐3‐(5‐methylisoxazol‐3‐yl)‐1,2,4‐triazole with substituted phenacyl bromide, aldehydes, p‐bromophenylisothiocyanate, aromatic carboxylic acids and oxalic acid, is described. The antibacterial activity of representative compounds was evaluated.     

4,5-二氢-1,2,4-三唑-5-硫酮席夫碱的合成和生物活性

以4-氨基-4,5-二氢-3-苯氧甲基-1氢-1,2,4-三唑-5-硫酮与取代苯甲醛为原料反应制得了9个新的三唑硫酮席夫碱类化合物,经IR、1H NMR和元素分析确定了各化合物结构。初步室内毒力测试结果表明该类化合物其具有较好的杀菌活性。     

A Novel Iron‐catalyzed One‐pot Synthesis of 3‐Amino‐1,2,4‐triazoles

A novel one‐pot synthesis of 3‐amino‐1,2,4‐triazole developed via iron (III) catalyzed route is reported. The new method is more efficient, simple, and convenient and presents a concise new strategy for the synthesis of 3‐amino‐1,2,4‐triazole derivatives. The iron (III) complex intermediate assisted in the intramolecular bond cyclization owing to its Lewis acidity or oxidizing properties. A series of aromatic nitriles bearing different electron‐donating and electron‐withdrawing groups substituted at para and/or ortho positions were also investigated. The position of the substituents affected the yield of the final compound, with the para‐substituted substrates giving relatively higher yields.     

Mercury(II) Chloride‐Mediated Desulphurization of Amidinothioureas: Synthesis and Antimicrobial Activity of 3‐Amino‐1,2,4‐triazole Derivatives

The synthesis of 3‐amino‐1,2,4‐triazole via mercury(II) chloride‐mediated cyclization of amidinothiourea is described. This procedure offers a general and efficient route to synthesize the title compound by 3 + 2 annulation reaction. On the basis of the literature precedence, the mechanism for the formation of 3‐amino‐1,2,4‐triazole is proposed. When the synthesized compounds were tested for their antimicrobial activity showed promising inhibition against tested microbes.     

Synthesis and antimicrobial evaluation of some 1,2,4‐triazole, 1,3,4‐oxa(thia)diazole,and 1,2,4‐triazolo[3,4‐b]‐1,3,4‐thiadiazine derivatives

3‐Methyl‐2‐benzofurancarboxylic acid hydrazide ( 2 ) reacts with carbon disulfide and pota‐ ssium hydroxide to give the corresponding potassium carbodithioate salt 3 . Treatment of the latter salt with hydrochloric acid, hydrazine hydrate, and with phen‐ acyl bromide afforded the corresponding 1,3,4‐oxadia‐ zole‐5‐thione 4 , 4‐amino‐1,2,4‐triazole‐5‐thione 5 , and thiazolidine‐2‐thione 9 derivatives, respectively. The reaction of either 1,3,4‐oxadiazole‐5‐thione 4 or 4‐amino‐1,2,4‐triazole‐5‐thione 5 with phenacyl bromide resulted in the formation of 1,2,4‐triazolo[3, 4‐b]‐1,3,4‐thiadiazine derivative 8 . Treatment of compounds 3 or 4 with hydrazonoyl halides 10a–d furn‐ ished the same 1,3,4‐thiadiazol‐2‐ylidene derivatives 11a–d . The 7‐arylhydrazono‐1,2,4‐triazolo[3,4‐ b ]‐1, 3,4‐thiadiazine derivatives 12a–d were obtained either by treatment of 4‐amino‐1,2,4‐triazole‐5‐thione 5 with hydrazonoyl halides 10a–d or by coupling of the 1,2,4‐triazolo[3,4‐b]‐1,3,4‐thiadiazine derivative 8 with diazonium salts. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:621–627, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20162     

Synthesis and Characterization of Bis(triaminoguanidinium) 5,5′‐Dinitrimino‐3,3′‐azo‐1H‐1,2,4‐triazolate – A Novel Insensitive Energetic Material

The synthesis of 5,5′‐diamino‐3,3′‐azo‐1H‐1,2,4‐triazole ( 3 ) by reaction of 5‐acetylamino‐3‐amino‐1H‐1,2,4‐triazole ( 2 ) with potassium permanganate is described. The application of the very straightforward and efficient acetyl protection of 3,5‐diamino‐1H‐1,2,4‐triazole allows selective reactions of the remaining free amino group to form the azo‐functionality. Compound 3 is used as starting material for the synthesis of 5,5′‐dinitrimino‐3,3′‐azo‐1H‐1,2,4‐triazole ( 4 ), which subsequently reacted with organic bases (ammonia, hydrazine, guanidine, aminoguanidine, triaminoguanidine) to form the corresponding nitrogen‐rich triazolate salts ( 5 – 9 ). All substances were fully characterized by IR and Raman as well as multinuclear NMR spectroscopy, mass spectrometry, and differential scanning calorimetry. Selected compounds were additionally characterized by low temperature single‐crystal X‐ray diffraction measurements. The heats of formation of 4 – 9 were calculated by the CBS‐4M method to be 647.7 ( 4 ), 401.2 ( 5 ), 700.4 ( 6 ), 398.4 ( 7 ), 676.5 ( 8 ), and 1089.2 ( 9 ) kJ · mol^–1. With these values as well as the experimentally determined densities several detonation parameters were calculated using both computer codes EXPLO5.03 and EXPLO5.04. In addition, the sensitivities of 5 – 9 were determined by the BAM drophammer and friction tester as well as a small scale electrical discharge device.     

Synthesis of Some 7H‐s‐Triazolo[3,4‐b]‐1,3,4‐thiadiazine Derivatives

The cyclization of 1‐amino‐2‐mercapto‐5‐[5‐methyl‐1‐(4‐methylphenyl)‐1,2,3‐triazol‐4‐yl]‐1,3,4‐triazole with various α‐haloketone in absolute ethanol yields 7H‐3‐[5‐methyl‐1‐(4‐methylphenyl)‐1,2,3‐triazol‐4‐yl]‐6‐substituted‐s‐triazolo[3,4‐b]‐1,3,4‐thiadiazines and their structures are established by elemental analysis, MS, IR and ¹H NMR spectral data.     

Studies with enaminones: synthesis of new coumarin‐3‐yl azoles,coumarin‐3‐yl azines,coumarin‐3‐yl azoloazines,coumarin‐3‐yl pyrone and coumarin‐2‐yl benzo[b]Furans

3‐Acetylcoumarine was condensed with dimethylformamide dimethylacetal (DMFDMA) to yield the enaminone, which reacts readily with hydroxylamine and with hydrazines to yield coumarin‐3‐ylisoxazoles and coumarin‐3‐ylpyrazoles respectively. Reaction of the enaminone with benzamidine hydrochloride and 3‐amino‐1,2,4‐1H‐triazole affords the pyrimidine and triazolo[3,4‐b]pyrimidine. The enaminone reacts with hippuric acid and with the dithiocarboxylic acid to yield pyranones. The reaction of the enaminone with 3‐amino‐1H‐1,2,4‐triazole gives the triazolo[3,4‐b]pyrimidine. The enaminone underwent self dimerization on reflux in acetic acid ammonium acetate to yield the coumarinyl pyridines and reacted with ketone under the same conditions to yield the pyridine. The reaction of the enaminone with 1,4‐benzoquinone and 1,4‐naphthoquinone gives benzofuryl coumarine derivatives.     

Synthesis and Antibacterial Activity of 3‐(5‐Methylisoxazol‐3‐yl) −1,2,4‐triazolo [3,4‐b]‐1,3,4‐thiadiazine Derivatives

The condensed products 2‐10 of 4‐amino‐5‐mercapto‐3‐(5‐methylisoxazol‐3‐yl)‐l,2,4‐triazole (1) with chloroacetaldehyde, 2‐bromocyclohexanone, chloranil, ωbromo‐ω‐(1H‐1, 2,4‐triazol‐l‐yl)acetophenone, 2‐bromo‐4′‐substituted acetophenones and 2‐bromo‐6′‐methoxy‐2′‐acetonaphthone were described. The antibacterial activities were also evaluated.     

Synthesis,characterization, and structural investigations of 1‐amino‐3‐substituted‐1,2,3‐triazolium salts,and a new route to 1‐substituted‐1,2,3‐triazoles

Quarternary salts based upon 3‐alkyl substituted 1‐amino‐1,2,3‐triazolium cations (alkyl = methyl, ethyl, nypropyl, 2‐propenyl, and n‐butyl) have been synthesized and characterized by vibrational spectra, multinuclear NMR, elemental analysis, and DSC studies. Subsequent diazotization of these salts results in the exclusive formation of 1‐alkyl‐1,2,3‐triazoles. Single crystal X‐ray studies were carried out for 1‐amino‐3‐methyl‐1,2,3‐triazolium iodide, 1‐amino‐3‐ethyl‐1,2,3‐triazolium bromide, 1‐amino‐3‐n‐propyl‐1,2,3‐triazolium bromide, and 1‐amino‐3‐n‐butyl‐1,2,3‐triazolium bromide as well as the starting heterocycle, 1‐amino‐1,2,3‐triazole, and all of the structures are discussed.     

Energetic Materials Based on 5,5′‐Diamino‐4,4′‐dinitramino‐3,3′‐bi‐1,2,4‐triazole

A simple and straightforward synthesis of 5,5′‐diamino‐4,4′‐dinitramino‐3,3′‐bi‐1,2,4‐triazole by the selective nitration of 4,4′,5,5′‐tetraamino‐3,3′‐bi‐1,2,4‐triazole is presented. The interaction of the amino and nitramino groups improves the energetic properties of this functionalized bitriazole. For a deeper investigation of these properties, various nitrogen‐rich derivatives were synthesized. The new compounds were investigated and characterized by spectroscopy (¹H and ¹³C NMR, IR, Raman), elemental analysis, mass spectrometry, differential thermal analysis (DTA), X‐ray analysis, and impact and friction sensitivities (IS, FS). X‐ray analyses were performed and deliver insight into structural characteristics with which the stability of the compounds can be explained. The standard enthalpies of formation were calculated for all compounds at the CBS‐4M level of theory, revealing highly positive heats of formation. The energetic performance of the new molecules was predicted with the EXPLO5 V6.02 computer. A small‐scale shock reactivity test (SSRT) and a toxicity test gave a first impression of the performance and toxicity of selective compounds.     

The effect of the coordination orientation of N atoms on polymeric structures: synthesis and characterization of one‐ and two‐dimensional CuII coordination polymers based on 4‐amino‐3‐(pyridin‐2‐yl)‐5‐[(pyridin‐3‐ylmethyl)sulfanyl]‐1,2,4‐triazole

Three new one‐ (1D) and two‐dimensional (2D) Cu^II coordination polymers, namely poly[[bis{μ₂‐4‐amino‐3‐(pyridin‐2‐yl)‐5‐[(pyridin‐3‐ylmethyl)sulfanyl]‐1,2,4‐triazole}copper(II)] bis(methanesulfonate) tetrahydrate], {[Cu(C₁₃H₁₂N₅S)₂](CH₃SO₃)₂·4H₂O}_n ( 1 ), catena‐poly[[copper(II)‐bis{μ₂‐4‐amino‐3‐(pyridin‐2‐yl)‐5‐[(pyridin‐4‐ylmethyl)sulfanyl]‐1,2,4‐triazole}] dinitrate methanol disolvate], {[Cu(C₁₃H₁₂N₅S)₂](NO₃)₂·2CH₃OH}_n ( 2 ), and catena‐poly[[copper(II)‐bis{μ₂‐4‐amino‐3‐(pyridin‐2‐yl)‐5‐[(pyridin‐4‐ylmethyl)sulfanyl]‐1,2,4‐triazole}] bis(perchlorate) monohydrate], {[Cu(C₁₃H₁₂N₅S)₂](ClO₄)₂·H₂O}_n ( 3 ), were obtained from 4‐amino‐3‐(pyridin‐2‐yl)‐5‐[(pyridin‐3‐ylmethyl)sulfanyl]‐1,2,4‐triazole with pyridin‐3‐yl terminal groups and from 4‐amino‐3‐(pyridin‐2‐yl)‐5‐[(pyridin‐4‐ylmethyl)sulfanyl]‐1,2,4‐triazole with pyridin‐4‐yl terminal groups. Compound 1 displays a 2D net‐like structure. The 2D layers are further linked through hydrogen bonds between methanesulfonate anions and amino groups on the framework and guest H₂O molecules in the lattice to form a three‐dimensional (3D) structure. Compound 2 and 3 exhibit 1D chain structures, in which the complicated hydrogen‐bonding interactions play an important role in the formation of the 3D network. These experimental results indicate that the coordination orientation of the heteroatoms on the ligands has a great influence on the polymeric structures. Moreover, the selection of different counter‐anions, together with the inclusion of different guest solvent molecules, would also have a great effect on the hydrogen‐bonding systems in the crystal structures.     

Synthesis of 6‐(5‐Methylisoxazol‐3yl)‐3‐alkyl Sulfanyl‐[1,2,4]triazolo‐[3,4‐b][1,3,4]thiadiazoles

A new series of isoxazole substituted fused triazolo‐thiadiazoles have been synthesized by the cyclocondensation of 5‐methylisoxazole‐3‐craboxylic acid and 4‐amino 1,2‐4‐triazole‐ 3,5‐dithiol using phosphorous oxychloride. The cyclised intermediate 6‐(5‐methylisoxazol‐3‐yl)‐[1,2,4]triazolo[3,4‐b][1,3,4]thiadiazole‐3‐thiol later on S‐alkylated with different alkyl halides in ethanol to give the title products in good to excellent yields.     

Synthesis and characterization of biologically active new Schiff bases containing 3‐functionalized 1,2,4‐triazoles and their zinc(II) complexes: crystal structure of 4‐bromo‐2‐[(E)‐(1H‐1,2,4‐triazol‐3‐ylimino)‐ methyl]phenol

Biologically active triazole Schiff bases ( L ¹  L ³ ) derived from the reaction of 3‐amino‐1,2,4‐triazole with chloro‐, bromo‐ and nitro‐ substituted salicylaldehydes and their Zn(II) complexes (1–3) have been synthesized and characterized by their physical, spectral and analytical data. Triazole Schiff bases potentially act as tridentate ligands and coordinate with the Zn(II) metal atom through salicylidene‐O, azomethine‐N and triazole‐N. The complexes have the general formula [M(L‐H)₂], where M = zinc(II) and L = ( L ¹ – L ³ ), and observe an octahedral geometry. The Schiff bases and their Zn(II) complexes have been screened for in‐vitro antibacterial, antifungal and brine shrimp bioassay. The biological activity data show the Zn(II) complexes to be more potent antibacterial and antifungal than the parent simple Schiff bases. Copyright © 2011 John Wiley & Sons, Ltd.     

A New pH Indicator Based on 2,5‐Diaryl‐1‐salicylideneamino‐1,3,4‐triazole Derivative

2‐Phenyl‐5‐p‐tolyl‐1‐salicylideneamino‐1,3,4‐triazole (PTST) was studied among 2,5‐diaryl‐1‐salicylidene amino‐1,3,4‐triazole derivatives as a novel potential pH indicator. In terms of absorption intensity coming from the acid‐base reactions, PTST showed strong yellow‐green colour with high extinction coefficient in the pH range 7.0–9.5. In addition, the corresponding colour development at the transition point can be attributed to the resonance structures of PTST, which were caused by the hydrogen ion dissociation from the acidic form of the compound in the presence of alkali. The full geometric optimization and achievement of the electronic structure of the molecule were performed by an AM1 semiempirical method. The triazole compound was compared with phenolphthalein (PT), which is widely used as an acid‐base indicator in titrimetry, for accuracy test.