微波促进下3-(2-苯并呋喃基)-4-氨基-5-巯基-1,2,4-三唑

微波辐射条件下, 首先由2-苯并呋喃甲酰肼依次与二硫化碳和水合肼反应合成3-(2-苯并呋喃基)-4-氨基-5-巯基- 1,2,4-三唑, 进一步在微波辐射条件下由4-氨基-5-巯基-1,2,4-三唑分别与芳甲酸/芳氧基乙酸、α-溴代苯乙酮及芳醛反应以较高产率制得了相应的1,2,4-三唑并[3,4-b]-1,3,4-噻二唑、1,2,4-三唑并[3,4-b]-1,3,4-噻二嗪及4-芳亚甲基亚胺基-5-巯基-1,2,4-三唑. 产物结构经IR, ¹H NMR, MS及元素分析进行了表征.     

型2,3-二氢-3-芳亚甲基-4-芳基-1,5-苯并硫氮杂的合成及表征

在盐酸和乙醇存在下, 苯乙酮、多聚甲醛以及N,N-二甲基甲酰胺进行Mannich反应, 得到了Mannich碱; 将其和1,2,4-三唑在水中反应, 得到含有1,2,4-三唑的苯丙酮; 然后, 在哌啶和甲苯存在下, 苯丙酮和苯甲醛进行羟醛缩合, 得到一系列含有1,2,4-三氮唑的查尔酮; 最后, 在三氟乙酸的催化下, 查尔酮和邻氨基硫酚发生亲核取代反应, 然后脱水缩合, 合成了一系列2,3-二氢-3-芳亚甲基-4-芳基-1,5-苯并硫氮杂. 其结构经IR, ¹H NMR, MS及元素分析确证.     

Coulometric determination of amine-substituted derivatives of 1,2,4-triazole in mono- and mixed-ligand complexes of metals

A procedure is developed for the coulometric determination of amine-substituted derivatives of 1,2,4-triazole. Stoichiometric coefficients of 1,2,4-triazoles and transition metal complexes with these ligands in bromination reactions are determined. The data obtained are used to determine the concentration of 4-amino-1,2,4-triazole in iron(II) mixed-ligand complexes of the composition Fe(TR)_3x(4-ATR)_{3 ? 3x}(ClO₄)₂, where TR is 1,2,4-triazole and 4-ATR is 4-amino-1,2,4-triazole that are characterized by the thermoinduced ¹A₁ ai ⁵T₂ spin transition and thermochromism (color change from pink to white and vice versa).     

Heterylation of 3-R1-5-R2-1,2,4-Triazoles with Derivatives of 3,5-Dinitro-1,2,4-Triazole

Heterylation of 3-R¹-5-R²-1'2'4-triazoles (pK _a 3-12) with N-alkyl-, N-alkenyl-, N-alkoxy-carbonyl-, N-oxoalkyl-, N-nitroxyalkyl, N-nitroaminoalkyl-3'5-dinitro-1'2'4-triazoles results insubstitution of a nitro group in 5 position of the dinitro compound yielding 1-R-methyl-3-nitro-5-(3-R¹-5-R²-1,2,4-triazolyl)-1,2,4-triazoles. The side processes: Hydroxide-ion attack on C⁵ and (or) N¹ of the ring both in the substrate and in the target compound afford 1-R-methyl3-nitro-1,2,4-triazol-5-ones, 3,5-dinitro-1,2,4-triazole and NH-acids of N-C-bitriazole series. Optimal reaction media are aprotic dipolar substances, and for compounds prone to heterolysis ethyl acetate-water systems. The azole pK _a is the decisive factor controlling the composition and the ratio of reaction products. The process is promising for azoles with pK _a > 5, and the optimal range of pK _a is 8-10.     

On the amination of 1,2,4-triazines by potassium amide in liquid ammonia and by phenyl phosphorodiamidate. A 15n-study

The amination of 5-R- and 6-R-3-X-1,2,4-triazines (R = C₆H₅, t-C₄H₉, X = SCH₃, SO₂CH₃, N⁺ (CH₃)₃, Cl) by potassium amide in liquid ammonia has been studied. In all reactions the formation of the corresponding 3-amino-1,2,4-triazines takes place; in some reactions by-products were found: from 5-phenyl- and 5-t-butyl-3-(methylthio)-1,2,4-triazine a ring contracted product i.e. 5-phenyl and 5-t-butyl-3-(methylthio)-1,2,4-triazole, from 6-phenyl-3-(methylthio)-1,2,4-triazine the dimer 3,3′-bis-(methylthio)-6,6′-bisphenyl-5,5′-bi-1,2,4-triazine and from 5-t-butyl-3-(trimethylammonio)-1,2,4-triazine chloride compound bis-(5-t-butyl-1,2,4-triazin-3-yl)- amine. Furthermore the conversion of 5-phenyl- and 5-t-butyl-1,2,4-triazin-3-one into the corresponding 3-amino compound by treatment with phenyl phosphorodiamidate (PPDA) was studied. A ¹⁵N study of these aminations showed that nearly all compounds undergo substitution according to both S_N(AE) and S_N(ANRORC) processes. The contribution of each of the competitive mechanisms to the amination is strongly influenced by the character of the leaving group.     

Synthesis and study of thermal stability of 3-nitro-1,2,4-triazole N-nitroxy-and N-azidomethyl derivatives

A method for the preparation of new 3-nitro-1,2,4-triazole derivatives has been suggested based on modification of the N-hydroxymethyl group by nitration and nucleophilic substitution reactions. Thermal stability of 3-nitro-1,2,4-triazole N-nitroxy- and N-azidomethyl derivatives, as well as of dinitrates, 5,5′-dinitro-2,2 ′-bisnitroxymethyl-2 H,2′H-3,3 ′-bi(1,2,4-triazole) and -(nitromethylene)bis(1,2,4-triazole), has been studied.     

Thermal decomposition of 4-amino-1,2,4-triazolium nitrate under infrared laser heating

The objective of this work is to study the behavior of an ionic liquid, 1-H-4-amino-1,2,4-triazolium nitrate, during thermal decomposition driven by an infrared laser (10.6 μm). The focus was to understand the initial decomposition reactions and subsequent reactions that lead to ring decomposition and eventually to ignition. A triple quadrupole mass spectrometer with molecular beam sampling was used to obtain gaseous decomposition species of the sample. The principal mass peaks that may contain multiple masses were analyzed through tandem mass techniques. The experiments were conducted at a laser heat flux of 100 W/cm² in helium at 1 atm. To assist in interpreting the data, three other materials were also tested, 4-amino-1,2,4-triazolium hydrochloride, 4-amino-1,2,4-triazole, and 1-H-1,2,4-triazole. The results show that the most probable route to initiate the decomposition of the 1-H-4-amino-1,2,4-triazolium nitrate is through proton transfer from N₁ site to the nitrate forming a neutral pair, nitric acid and amino-triazole. Subsequent reactions involve decomposition of the neutral pair and their interactions.     

Notiz über die Reaktion von Methylhydrazin mit N-Cyano-azomethinen. Abhängigkeit des Reaktionsverlaufs von der Natur der Abgangsgruppe

The reaction of methylhydrazine with N-cyanoazomethines 1 containing a thioalkyl leaving group yields the 3-amino-1,2,4-triazole derivatives 2 , whereas the N-cyanoazomethines 1 containing an alkoxy leaving group give the isomeric 5-amino-1,2,4-triazoles 3. The yields are excellent and the position selectivity is high. The structures of the 1,2,4-triazole derivatives were determined with the aid of proton-coupled ¹³C-NMR. spectra.     

Spectroscopic identification of some derivatives of 3,4-diamino-4H-1,2,4-triazole and 3-Hydrazino-4H-1,2,4-triazole

Spectroscopic methods (ir, ¹H- and ¹³C-nmr, ms and uv) have been used for the structural elucidation and identification of different isomeric 1,2,4-triazole derivatives, obtained by cyclisation reactions from appropriate diaminoguanidines. The four compounds 3,4-diamino-4H-1,2,4-triazole, 3-hydrazino-4H-1,2,4-triazole, 3-amino-4-(2,6-dichlorobenzylideneamino)-4H-1,2,4-triazole and 3-(2,6-dichlorobenzylidenehydrazino)-4H-1,2,4-triazole, were chosen as representative structures to illustrate the general spectroscopic properties for 3,4-diamino- and 3-hydrazino-substituted 4H-1,2,4-triazoles and the corresponding hydrazones, with different substituents in the 5-position of the triazole ring (alkyl-, aralkyl-, mercapto-, hydroxy- and amino-groups). Nmr and uv spectroscopy were found to be the best methods for confirmation of the different series of hydrazones, while ir and nmr were found to be suitable for the structural elucidation of compounds in the series of 3,4-diamino- and 3-hydrazino-4H-1,2,4-triazoles, respectively.     

Thermodynamic and Kinetic Studies on Reactions of Pt(II) Complexes with Pyrazole,Pyridazine, and 1,2,4-Triazole

Summary. Substitution reactions of the complexes [Pt(dien)H₂O]²⁺ and [PtCl(dien)]⁺, where dien = diethylentriamine or 1,5-diamino-3-azapentane, with some nitrogen-donor ligands such as 1,2,4-triazole, pyrazole, and pyridazine, were studied in an aqueous 0.10 M NaClO₄ at pH = 2.5 using variable-temperature spectrophotometry and ¹H NMR spectroscopy. The second-order rate constants indicate that the aqua complex, [Pt(dien)H₂O]²⁺, is more reactive than the corresponding chloro complex, [PtCl(dien)]⁺. The reactivity of the used ligands follows the order: 1,2,4-triazole > pyridazine > pyrazole. Activation parameters were determined for all reactions and the negative entropies of activation (ΔS ^≠) support an associative ligand substitution mechanism.     

Thermodynamic and Kinetic Studies on Reactions of Pt(II) Complexes with Pyrazole, Pyridazine, and 1,2,4-Triazole

Substitution reactions of the complexes [Pt(dien)H₂O]²⁺ and [PtCl(dien)]⁺, where dien = diethylentriamine or 1,5-diamino-3-azapentane, with some nitrogen-donor ligands such as 1,2,4-triazole, pyrazole, and pyridazine, were studied in an aqueous 0.10 M NaClO₄ at pH = 2.5 using variable-temperature spectrophotometry and ¹H NMR spectroscopy. The second-order rate constants indicate that the aqua complex, [Pt(dien)H₂O]²⁺, is more reactive than the corresponding chloro complex, [PtCl(dien)]⁺. The reactivity of the used ligands follows the order: 1,2,4-triazole > pyridazine > pyrazole. Activation parameters were determined for all reactions and the negative entropies of activation (ΔS ^≠) support an associative ligand substitution mechanism.     

Equilibrium and Kinetic Studies on Ligand Substitution Reactions of Trans-[COIII(en)2(Me)H2O]2+: A Model for Coenzyme B12

Ligand substitution of trans-[Co^III(en)₂(Me)H₂O]²⁺ was studied for pyrazole, 1,2,4-triazole and N-acetylimidazole as entering nucleophiles. These displace the coordinated H₂O molecule trans to the methyl group to form trans-[Co(en)₂(Me)azole]. Stability constants at 18°C for the substitution of H₂O by pyrazole, 1,2,4-triazole and N-acetylimidazole are 0.7 ± 0.1, 13.8 ± 1.4 and 1.7 ± 0.2 M^?1, respectively. Second order rate constants at the same temperature for the reaction of trans-[Co^III(en)₂(Me)H₂O]²⁺ with pyrazole, 1,2,4-triazole and N-acetylimidazole are 161 ± 12, 212 ± 11 and 12.9 ± 1.6 M^?1 s^?1, respectively. Activation parameters (ΔH^≠, ΔS^≠) are 67 ± 6 kJ mol^?1, + 27 ± 19 J K^?1 mol^?1; 59 ± 2 kJ mol^?1, + 1 ± 6 J K^?1 mol^?1 and 72 ± 4 kJ mol^?1, + 23 ± 14 J K^?1 mol^?1 for reactions with pyrazole, 1,2,4-triazole and N-acetylimidazole, respectively. Substitution of coordinated H₂O by azoles follows an I_d mechanism.     

Die Acylierung von 5-Amino-1 H-1, 2, 4-triazolen. Eine 13C-NMR.-Studie

The Acylation of 5-Amino-1 H-1,2,4-triazoles. A ¹³C-NMR. Study The acylation of 3-substituted-5-amino-1 H-1,2,4-triazoles (1) with methyl chloroformate or dimethylcarbamoyl chloride yielded mainly 1-acyl-5-amino-1,2,4-triazoles ( 2 and 3 ). Acylation of 3-methyl-, 3-methoxy- and 3-methylthio-5-amino-1 H-1,2,4-triazole ( 1b , 1c and 1d ) with methyl chloroformate gave up to 10% of the 1-acyl-3-amino-1,2,4-triazoles. For the unsubstituted 5-amino-1,2,4-triazole (1a) , a (1:1)-mixture of the 3- and 5-isomers 2a and 4 was obtained in dioxane in the presence of triethylamine. No 4-acylated product was detected in contrast to earlier reports. The structures of the reaction products were determined with the aid of proton coupled ¹³C-NMR. spectra using the corresponding N-methyl-1,2,4-triazoles as reference compounds.     

Reaction of thiosemicarbazide with n-cyanoguanidine: synthesis of 3,5-diamino-1-thiocarbamoyl-and 3,5-diamino-1-thiazol-2-yl-1,2,4-triazoles

The reaction of thiosemicarbazide with N-cyanoguanidine in an acidic medium afforded 3,5-diamino-1-thiocarbamoyl-1,2,4-triazole, whose condensation with α-halo ketones gave 3,5-diamino-1-thiazol-2-yl-1,2,4-triazoles 7a–d. The latter were also prepared by the independent synthesis from 2-hydrazinothiazoles and N-cyanoguanidine. Acylation of compounds 7a,d under mild conditions and their condensation with aldehydes occur at the C(3′)NH₂group. The structure of aroyl derivative 11c was established by X-ray diffraction. Acylation of diaminothiazolyltriazole 7a in boiling Ac₂O afforded 3,5-diacetylamino-1-(4-phenylthiazol-2-yl)-1,2,4-triazole. Hydrogenation of arylidene derivatives 14b,c and aroyl derivative 11c gave the corresponding benzylaminotriazoles 15a,b. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 329–334, February, 2006.     

Reactions of 2-aryl-4-arylidene-4<Emphasis Type="Italic">H</Emphasis>-oxazol-5-ones with 3-amino-1,2,4-triazole, 5-aminotetrazole,and 2-aminobenzimidazole

The reactions of 3-amino-1,2,4-triazole, 5-aminotetrazole, and 2-aminobenzimidazole with 2-aryl-4-arylidene-4H-oxazol-5-ones (azlactones) were studied. The electron-releasing properties of the azole ring were demonstrated to influence the reaction pathway of azlactones with aminoazoles. The structures of the resulting compounds were established by ¹H and ¹³C NMR spectroscopy using spin-spin decoupling and the nuclear Overhauser effect.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2730–2733, December, 2004.     

A novel two‐dimensional nickel(II) coordination polymer with 1,4‐bis(1,2,4‐triazol‐1‐ylmethyl)benzene and azide ligands

The coordination geometry of the Ni^II atom in the title complex, poly[diazidobis[μ‐1,4‐bis(1,2,4‐triazol‐1‐ylmethyl)benzene‐κ²N⁴:N^4′]nickel(II)], [Ni(N₃)₂(C₁₂H₁₂N₆)₂]_n, is a distorted octahedron, in which the Ni^II atom lies on an inversion centre and is coordinated by four N atoms from the triazole rings of two symmetry‐related pairs of 1,4‐bis(1,2,4‐triazol‐1‐ylmethyl)benzene (bbtz) ligands and two N atoms from two symmetry‐related monodentate azide ligands. The Ni^II atoms are bridged by four bbtz ligands to form a two‐dimensional (4,4)‐network.     

A Co‐MOF with a (4,4)‐connected binodal two‐dimensional topology: synthesis,structure and photocatalytic properties

The Co‐MOF poly[[diaqua{μ₄‐1,1,2,2‐tetrakis[4‐(1H‐1,2,4‐triazol‐1‐yl)phenyl]ethylene‐κ⁴N:N′:N′′:N′′′}cobalt(II)] benzene‐1,4‐dicarboxylic acid benzene‐1,4‐dicarboxylate], {[Co(C₃₄H₂₄N₁₂)(H₂O)₂](C₈H₄O₄)·C₈H₆O₄}_n or {[Co(ttpe)(H₂O)₂](bdc)·(1,4‐H₂bdc)}_n, (I), was synthesized by the hydrothermal method using 1,1,2,2‐tetrakis[4‐(1H‐1,2,4‐triazol‐1‐yl)phenyl]ethylene (ttpe), benzene‐1,4‐dicarboxylic acid (1,4‐H₂bdc) and Co(NO₃)₂·6H₂O, and characterized by single‐crystal X‐ray diffraction, IR spectroscopy, powder X‐ray diffraction (PXRD), luminescence, optical band gap and valence band X‐ray photoelectron spectroscopy (VB XPS). Co‐MOF (I) shows a (4,4)‐connected binodal two‐dimensional topology with a point symbol of {4⁴·6²}{4⁴·6²}. The two‐dimensional networks capture free neutral 1,4‐H₂bdc molecules and bdc^2? anions, and construct a three‐dimensional supramolecular architecture via hydrogen‐bond interactions. MOF (I) is a good photocatalyst for the degradation of methylene blue and rhodamine B under visible‐light irradiation and can be reused at least five times.     

A novel two‐dimensional cobalt(II) coordination polymer with 1,4‐bis(1,2,4‐triazol‐1‐yl­methyl)­benzene

In the crystal structure of the title complex, poly­[[di­azidocobalt(II)]‐di‐μ‐1,4‐bis(1,2,4‐triazol‐1‐yl­methyl)­benzene‐κ⁴N⁴:N^4′], [Co(N₃)₂(bbtz)₂]_n, where bbtz is 1,4‐bis(1,2,4‐triazol‐1‐yl­methyl)­benzene (C₁₂H₁₂N₆), the Co^II atom, which lies on an inversion centre, is six‐coordinated by four N atoms from four bbtz ligands and by two N atoms from two azide ligands, in a distorted octahedral coordination environment. The Co^II atoms are bridged by four bbtz ligands to form a two‐dimensional [4,4]‐network.     

Structural characterisation of mononuclear zinc(ii) complexes of 4-methyl-3,5-di(2-pyridyl)-4H-1,2,4-triazole with three-atom co-ligands: [ZnII(medpt)2X]ClO4 (X?=?NCS?, N3?, NO2?)

The reaction of 4-methyl-3,5-di(2-pyridyl)-4H-1,2,4-triazole (medpt) with Zn(ClO₄)₂·6H₂O and NaSCN, NaN₃ or NaNO₂ in a 2:1:1 molar ratio in MeOH/H₂O (9:1) affords the mononuclear complexes [Zn^II(medpt)₂(NCS)]ClO₄, [Zn^II(medpt)₂(N₃)]ClO₄ and [Zn^II(medpt)₂(NO₂)]ClO₄, respectively. All three complexes have been structurally characterised and found to feature unusual coordination polyhedra for 3,5-di(2-pyridyl)-4H-1,2,4-triazole complexes. In [Zn^II(medpt)₂(NCS)]ClO₄ and [Zn^II(medpt)₂(N₃)]ClO₄, the zinc atom resides within a distorted square-pyramidal N₅ coordination sphere [τ = 0.22 and 0.04, respectively] with two bidentate medpt ligands bound equatorially and the pseudohalide ion coordinating as a unidentate co-ligand in the apical position. In contrast, the NO₂ ⁻ ion in [Zn^II(medpt)₂(NO₂)]ClO₄ acts as a bidentate ligand, which leads to a strongly distorted N₄O₂ coordination environment about the metal centre.     

Thermal decomposition mechanisms of nitro-1,2,4-triazoles: A theoretical study

Possible decomposition mechanisms of C-nitro-and N-nitro-1,2,4-triazoles were simulated. We showed that in addition to the experimentally detected thermolysis products including N₂, N₂O, NO, CO₂, HCN, HNCO, 1,2,4-triazole, 3(5)-nitroso-1,2,4-triazole, and 1,2,4-triazolone, some other decompositon products (H₂O, CO, NO₂, cyanamide, cyanuric acid, and melamine) can be formed. Using the density functional approach (B3LYP/6-31G* approximation), we assessed the most favorable thermal decomposition pathways of nitrotriazoles and studied the relationships between the thermolysis pathways of these substances and their molecular and electronic structures. We found a correlation between the energy gap width (energy difference between the frontier molecular orbitals) and the stabilities of the C-nitro-1,2,4-triazole tautomers to thermal decomposition. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1338–1358, August, 2006.