- C-(β-d-Glucopyranosyl)formamidrazones, formic acid hydrazides and their transformations into 3-(β-d-glucopyranosyl)-5-substituted-1,2,4- triazoles: A synthetic and computational study
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Synthesis of O-perbenzoylated 3-(β-d-glucopyranosyl)-5-substituted-1, 2,4-triazoles, precursors of potent inhibitors of glycogen phosphorylase, was studied by ring closures of N1-acyl-carboxamidrazone type intermediates. Reactions of C-(β-d-glu
- Bokor, éva,Fekete, Attila,Varga, Gergely,Szocs, Béla,Czifrák, Katalin,Komáromi, István,Somsák, László
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Read Online
- PEG-supported synthesis of 3,5-disubstituted 1,2,4-triazoles
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1,3-Dipolar cycloadditions between diethyl azodicarboxylate and the polymer-bound munchnones generated from the corresponding carboxylic acids provided a library of 3,5-disubstituted 1,2,4-triazoles in excellent yield and high purity.
- Wang, Jun-Ke,Zong, Ying-Xiao,Yue, Guo-Ren
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Read Online
- The Synthesis of 1,3,5-Thiadiazinylium Salts
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1,3,5-Thiadiazinylium salts were synthesized in good yields by the reaction of N-acyl imidoyl chlorides with thioamides or the treatment of 4H-1,3,5-thiadiazines with trityl salts.
- Shibuya, Isao
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Read Online
- Liquid-phase traceless synthesis of 3,5-disubstituted 1,2,4-triazoles
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A liquid-phase traceless route to 3,5-disubstituted-1,2,4-triazoles has been developed, which allows for the incorporation of two elements of diversity. The heterocycle was constructed upon PEG6000 (soluble polymer) modified by 4-hydroxy-2-methoxy-benzaldehyde, from which a traceless cleavage could be realized with TFA-CH2Cl2. This method provided a library of 3,5-disubstituted-1,2,4-triazoles with high yields and purity. Georg Thieme Verlag Stuttgart.
- Wang, Xi-Cun,Wang, Jun-Ke,Wu, Dong-Qing,Zong, Ying-Xiao
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Read Online
- Solid phase synthesis of 1,2,4-triazoles under microwave irradiation
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1,2,4-Triazoles (3a-g) have been prepared from three component condensation reaction of acid hydrazide (1), S-methyl isothioamide hydroiodide (2), and ammonium acetate on the surface of silica gel under microwave irradiation.
- Rostamizadeh, Shahnaz,Tajik, Hasan,Yazdanfarahi, Soheila
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Read Online
- 1,2,4-Triazolato paddlewheel dibismuth complexes with very short Bi(ii)-Bi(ii) bonds: Bismuth(iii) oxidation of 1,2,4-triazolato anions into neutral: N -1,2,4-triazolyl radicals
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Bismuth(iii) oxidation of 3,5-di-substituted-1,2,4-triazolato anions afforded a paddlewheel 1,2,4-triazolato dibismuth complex [L2(Bi-Bi)L2] (L = η1,η1-3,5-R2tz, R = Ph (3), iPr (4)) with very short Bi(ii)-Bi(ii) bonds (2.8650(4)-2.8721(3) ?). The reaction involved the intermediates of the organobismuth radical [Bi(R2tz)2] and neutral N-1,2,4-triazolyl radical [3,5-R2tz]. The dimerization of the former produced the corresponding dibismuth complex while the latter was trapped by using spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) to give the radical adduct of {(3,5-R2tz)(DMPO)} which was unambiguously evidenced by EPR analysis.
- He, Ru-Ru,Li, Li,Ma, Jian-Ping,Su, Ji-Hu,Zhang, Xiang,Zhao, Ming-Gang,Zheng, Wenjun
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Read Online
- A base-catalyzed, direct synthesis of 3,5-disubstituted 1,2,4-triazoles from nitriles and hydrazides
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A convenient and efficient one step, base-catalyzed synthesis of 3,5-disubstituted 1,2,4-triazoles by the condensation of a nitrile and a hydrazide is presented. A diverse range of functionality and heterocycles are tolerated under the reaction conditions
- Yeung, Kap-Sun,Farkas, Michelle E.,Kadow, John F.,Meanwell, Nicholas A.
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Read Online
- Iodine Catalyzed Oxidative Coupling of Diaminoazines and Amines for the Synthesis of 3,5-Disubstituted-1,2,4-Triazoles
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A simple, convenient, transition metal-free one pot synthesis of 3,5-disubstituted-1,2,4-triazoles has been established. The innovation in this reaction is the use of easily available 1,1-diaminoazines as substrates. This method provides the products with wider substrate scope, at an expedited rate, and with relatively better yields in comparison to the reported methods. The reaction mechanism involves an initial intermolecular nucleophilic addition (facilitated by I2) followed by intramolecular nucleophilic cyclization.
- Beifuss, Uwe,Bharatam, Prasad V.,Chourasiya, Sumit S.,Kathuria, Deepika,Sahoo, Subash C.,Wani, Aabid A.
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p. 7659 - 7671
(2021/06/25)
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- A practical base mediated synthesis of 1,2,4-triazoles enabled by a deamination annulation strategy
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A rapid and efficient base mediated synthesis of 1,3,5-trisubstituted 1,2,4-triazoles has been developed using the annulation of nitriles with hydrazines, which can be expanded to a wide range of triazoles in good to excellent yields. Ammonia gas is liberated during the reaction, and halo and hetero functional groups as well as free hydroxyl and amino groups are tolerated in this transformation. A variety of alkyl and aryl-substituted nitriles can be functionalized with aromatic and aliphatic hydrazines employing this procedure. This finding provides a practical and useful strategy for the synthesis of various 15N-labeled 1,2,4-triazole derivatives, and two types of mGlu5 receptor pharmaceuticals can be easily assembled in a one-pot manner. This journal is
- Zhang, Chunyan,Liang, Zuyu,Jia, Xiaofei,Wang, Maorong,Zhang, Guoying,Hu, Mao-Lin
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supporting information
p. 14215 - 14218
(2020/11/24)
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- Green aqueous synthesis and antimicrobial evaluation of 3,5-disubstituted 1,2,4-triazoles
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[Figure not available: see fulltext.] An eco-friendly and simple procedure was proposed for the synthesis of 3,5-disubstituted 1,2,4-triazoles by optimized reaction of benzamidine hydrochloride and various aryl hydrazides. H2O and K2
- Beyzaei, Hamid,Malekraisi, Farideh,Aryan, Reza,Ghasemi, Behzad
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p. 482 - 487
(2020/05/25)
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- Method for preparing 1,3,5-trisubstituted-1,2,4-triazole derivative in one step
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The invention discloses a method for preparing a 1,3,5-trisubstituted-1,2,4-triazole derivative in one step, and belongs to the technical field of organic chemical synthesis. According to the method,a simple nitrile compound and a hydrazine compound are u
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Paragraph 0026; 0096-0100; 0296-0300
(2020/08/12)
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- TBHP/TBAI–Mediated simple and efficient synthesis of 3,5-disubstituted and 1,3,5-trisubstituted 1H-1,2,4-triazoles via oxidative decarbonylation of aromatic aldehydes and testing for antibacterial activities
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The author has developed a simple, efficient and eco–friendly convenient general method for synthesis of 3,5–disubstituted–1,2,4–triazoles and 1,3,5–trisubstituted–1,2,4–triazoles from 3–monosubstituted–1,2,4–triazoles and 1,3–disubstituted–1,2,4–triazoles respectively using tetrabutylammonium iodide (TBAI) as catalyst and TBHP as oxidant under mid reaction conditions. This method provides structurally diverse 3,5–disubstituted 1,2,4–triazoes and 1,3,5––trisubstituted–1,2,4–triazoles in good to excellent yields. 3,5–Disubstituted 1,2,4–triazoes and 1,3,5––trisubstituted–1,2,4–triazoles derivatives are biologically and pharmaceutically active molecules, and therefore, this protocol could be of wide applications in medicinal chemistry and organic chemistry.
- Agisho, Habtamu Abebe,Esatu, Habdolo,Hairat, Suboot,Zaki, Mehvash
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supporting information
(2020/05/19)
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- CONDENSED CYCLIC COMPOUND AND ORGANIC LIGHT-EMITTING DEVICE INCLUDING THE SAME
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A condensed cyclic compound represented by Formula 1: [in-line-formulae]Ar1-(L1)m1-Ar2??Formula 1[/in-line-formulae]wherein, in Formula 1, Ar1, Ar2, L1, and ml are the same as described in the specification.
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Paragraph 0283-0285
(2019/11/12)
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- Heterogeneous Copper(I)-Catalyzed Cascade Addition-Oxidative Cyclization of Nitriles with 2-Aminopyridines or Amidines: Efficient and Practical Synthesis of 1,2,4-Triazoles
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The heterogeneous cascade addition-oxidative cyclization of nitriles with 2-aminopyridines or amidines was achieved in 1,2-dichlorobenzene or DMSO at 120-130 °C by using a 1,10-phenanthroline-functionalized MCM-41-supported copper(I) complex [Phen-MCM-41-
- Xia, Jianhui,Huang, Xue,Cai, Mingzhong
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p. 2014 - 2022
(2019/04/26)
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- Development of novel liver?X?receptor modulators based on a 1,2,4-triazole scaffold
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Liver X Receptor (LXR) agonists have been reported as a potential treatment for atherosclerosis, Alzheimer's disease and hepatitis C virus (HCV) infection. We have designed and synthesized a series of potent compounds based on a 1,2,4-triazole scaffold as novel LXR modulators. In cell-based cotransfection assays these compounds generally functioned as LXR agonists and we observed compounds with selectivity towards LXRα (7-fold) and LXRβ (7-fold) in terms of potency. Assessment of the effects of selected compounds on LXR target gene expression in HepG2 cells revealed that compounds 6a-b and 8a-b behaved as inverse agonists on FASN expression even though they were agonists in the LXRα and LXRβ cotransfection assays. Interestingly, these compounds had no effect on the expression of SREBP-1c confirming a unique LXR modulator pharmacology. Molecular docking studies and evaluation of ADME properties in-silico show that active compounds possess favorable binding modes and ADME profiles. Thus, these compounds may be useful for in vivo characterization of LXR modulators with unique profiles and determination of their potential clinical utility.
- Goher, Shaimaa S.,Griffett, Kristine,Hegazy, Lamees,Elagawany, Mohamed,Arief, Mohamed M.H.,Avdagic, Amer,Banerjee, Subhashis,Burris, Thomas P.,Elgendy, Bahaa
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supporting information
p. 449 - 453
(2019/01/04)
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- One pot solvent-free solid state synthesis, photophysical properties and crystal structure of substituted azole derivatives
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A solvent-free solid state method has been developed to synthesize three series of substituted azole derivatives (including 1,3,4-oxadiazole, 1,3,4-thiadiazole and 1,2,4-triazole) in high yields by condensation cyclization of N,N′-bishydrazide derivatives with corresponding cyclization agents, respectively. This general method avoids the use of organic solvents, saves cost and resources, simplifies post-processing and increases reaction rates. These compounds have been fully characterized by 1H NMR, 13C NMR, elemental analysis and MS. The structure of 2,5-di (4-tertbutylphenyl)-1,3,4-oxadiazole has been determined by single crystal X-ray diffraction analysis. The cell parameters are as follows: monoclinic crystal system, Cc space group, a = 18.735 (2) ?, b = 6.3375 (8) ?, c = 16.824 (2) ? and α = γ = 90°; β = 98.292 (2). The electronic absorption and fluorescent properties of these compounds have been systematically investigated for the first time. The relationships between heterocyclic structures and photophysical properties have been discussed. The alteration of emission and absorption wavelengths can be elucidated by hybrid atoms' electronegativity and Substituents' Hammett constants. This approach proposes a novel insight to provide a great number of novel substituted azole derivatives with good photophysical properties by a general green method.
- Du, Yanting,Wan, Zilu,Chen, Lianqing,Wu, Lamei
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p. 315 - 325
(2019/05/27)
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- Visible light-induced cyclization reactions for the synthesis of 1,2,4-triazolines and 1,2,4-triazoles
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A novel method for concisely synthesizing 1,2,4-triazolines via [3+2] cyclization under visible light is reported. These compounds can be easily converted into 1,2,4-triazoles under basic or photoredox conditions. The application of the 1,2,4-triazoles was also investigated via mild operations.
- Wang, Hongyu,Ren, Yanfei,Wang, Kaiye,Man, Yunquan,Xiang, Yanan,Li, Na,Tang, Bo
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p. 9644 - 9647
(2017/09/01)
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- Condensed cyclic compound and organic light-emitting device including the same
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Disclosed are a condensed-cyclic compound and an organic light-emitting device comprising the same. The condensed-cyclic compound is represented by chemical formula 1. The condensed-cyclic compound has excellent electrical properties and thermal stability. The organic light-emitting device comprising the condensed-cyclic compound can have a low driving voltage, high efficiency, high luminance, long lifespan, and properties of high color purity.COPYRIGHT KIPO 2016
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Paragraph 0334; 0335; 0336
(2016/10/08)
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- A 1, 2, 4-triazole derivative synthesis method
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The invention provides a 1,2,4-triazole derivative and a preparation method thereof. The method comprises the following steps: after mixing amidine or o-aminopyridine with a nitrile compound, copper acetate monohydrate, phenanthroline and sodium carbonate, adding an organic solvent; reacting for 12-24 hours in air at 110-120 DEG C; extracting the obtained product by ethyl acetate; drying by anhydrous sodium sulfate; decompressing and concentrating to obtain a coarse product; carrying out column chromatography isolation to obtain the 1,2,4-triazole derivative. Compared with the prior art, the method provided by the invention has the advantages that (1) the method is carried out in an air atmosphere, so that the cost is low; (2) no noble metals, strong bases and organic oxidizing agents are used but copper acetate monohydrate is used as a catalyst, so that the cost is saved; (3) by using amine and nitrile as reaction raw materials, the raw materials are easy to obtain; (4) the synthetic method is high in efficiency, wide in using range and suitable for various substrate reactions.
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Paragraph 0098-0100
(2016/12/01)
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- I2 mediated one-pot synthesis of 1,2,4-triazoles from amidines and imidates
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A one-pot facile synthesis of 3,5-disubstituted-1H-1,2,4-triazole derivatives using I2/Cs2CO3 has been described. The method involves readily available inexpensive reagents and is applicable to a wide range of substrates.
- Inturi, Surendra Babu,Kalita, Biswajit,Ahamed, A. Jafar
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supporting information
p. 2227 - 2230
(2016/05/10)
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- Copper-catalyzed one-pot synthesis of 1,2,4-triazoles from nitriles and hydroxylamine
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A simple and efficient copper-catalyzed one-pot synthesis of substituted 1,2,4-triazoles through reactions of two nitriles with hydroxylamine has been developed. The protocol uses simple and readily available nitriles and hydroxylamine hydrochloride as th
- Xu, Hao,Ma, Shuang,Xu, Yuanqing,Bian, Longxiang,Ding, Tao,Fang, Xiaomin,Zhang, Wenkai,Ren, Yanrong
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p. 1789 - 1794
(2015/02/19)
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- Facile synthesis of 3,5-diaryl-1,2,4-triazoles via copper-catalyzed domino nucleophilic substitution/oxidative cyclization using amidines or imidates as substrates
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Two methods for the synthesis of 3,5-diaryl-1,2,4-triazoles, both domino reactions, are reported. The first procedure, the Cu(OTf)2-catalyzed reaction between two amidines using NaHCO3 as a base, 1,10-phenanthroline as an additive and K3[Fe(CN)6]/ atmospheric oxygen as the oxidant, delivers 3,5-diaryl-1,2,4-triazoles with yields up to 68%. The second procedure for the synthesis of 3,5-diaryl-1,2,4- triazoles with yields up to 64% rests on the Cu(OTf)2-catalyzed reaction between two imidates and ammonium carbonate. This method features the formation of three bonds in a single synthetic step.
- Sudheendran, Kavitha,Schmidt, Dietmar,Frey, Wolfgang,Conrad, Jürgen,Beifuss, Uwe
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p. 1635 - 1645
(2014/02/14)
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- An efficient and recyclable heterogeneous catalytic system for the synthesis of 1,2,4-triazoles using air as the oxidant
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Copper-zinc supported on Al2O3-TiO2 was found as a simple and efficient heterogeneous catalyst for the oxidative synthesis of 1,2,4-triazole derivatives using air as the green oxidant under ligand-, base- and additive-free conditions. The heterogeneous reactions carried out smoothly with a large range of substrates, including NO2-, vinyl-, pyrimidine- and imidazole-contained starting materials, and provided corresponding triazoles in moderate to excellent yields with low catalyst loading (1.6 mol%). Furthermore, the catalyst can be simply recycled many times without significant loss in catalytic activity. The Royal Society of Chemistry.
- Meng, Xu,Yu, Chaoying,Zhao, Peiqing
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p. 8612 - 8616
(2014/03/21)
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- Efficient in situ synthesis of 3,5-disubstituted-1,2,4-triazoles under microwave-assisted conditions
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Abstract Based on an efficient in situ metal/ligand reaction, a serial of 3,5-disubstituted-1, 2,4-triazoles were synthesized via cycloaddition of organonitriles and ammonia under microwave conditions. This synthetic protocol provides a concise and high-yield access to 3,5-disubstituted-1,2,4-triazoles in organic synthesis. Moreover, the tautomerism of the product was also investigated. Taylor & Francis Group, LLC.
- Wei, Qing,Qiao, Chengfang,Xia, Zhengqiang,Chen, Sanping
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p. 3181 - 3191
(2014/01/06)
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- NOVEL COMPOUNDS
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This invention relates to compounds of formula I their use as positive allosteric modulators of mGlu5 receptor activity, pharmaceutical compositions containing the same, and methods of using the same as agents for treatment and/or prevention of neurological and psychiatric disorders associated with glutamate dysfunction such as schizophrenia or cognitive decline such as dementia or cognitive impairment. A, B, X, R1, R2, R3 have meanings given in the description.
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Paragraph 0474; 0475; 0476
(2013/06/27)
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- 1,2,4 -TRIAZOLES AS ALLOSTERIC MODULATORS OF MGLU5 RECEPTOR ACTIVITY FOR THE TREATMENT OF SCHIZOPHRENIA OF DEMENTIA
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This invention relates to compounds of formula (I) their use as positive allosteric modulators of mGlu5 receptor activity, pharmaceutical compositions containing the same, and methods of using the same as agents for treatment and/or prevention of neurological and psychiatric disorders associated with glutamate dysfunction such as schizophrenia or cognitive decline such as dementia or cognitive impairment. A, B, X, R1, R2, R3 have meanings given in the description.
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Page/Page column 107-108
(2013/06/27)
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- SUBSTITUTED TRIAZOLES AND THEIR USE FOR TREATMENT AND/OR PREVENTION NEUROLOGICAL AND PSYCHIATRIC DISORDERS
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This invention relates to compounds of formula (I), their use as positive allosteric modulators of mGlu5 receptor activity, pharmaceutical compositions containing the same, and methods of using the same as agents for treatment and/or prevention of neurological and psychiatric disorders associated with glutamate dysfunction such as schizophrenia or cognitive decline such as dementia or cognitive impairment. A, B, Ar, R1, R2, R3 have meanings given in the description.
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Page/Page column 66
(2013/07/31)
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- NOVEL COMPOUNDS
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This invention relates to compounds of formula I their use as positive allosteric modulators of mGlu5 receptor activity, pharmaceutical compositions containing the same, and methods of using the same as agents for treatment and/or prevention of neurological and psychiatric disorders associated with glutamate dysfunction such as schizophrenia or cognitive decline such as dementia or cognitive impairment. A, B, Ar, R1, R2, R3 have meanings given in the description.
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Paragraph 0340; 0341; 0342
(2013/07/25)
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- Copper-mediated sequential C-N and N-N bond formation: Facile synthesis of symmetrical 1,2,4-triazoles
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Via a one-pot process, catalyzed by Cu(OAc)2, a series of 3,5-disubstituted 4H-1,2,4-triazoles was conveniently and efficiently synthesized by using low-toxicity, stable, readily available, inexpensive amidine hydrochloride. Georg Thieme Verlag Stuttgart New York.
- Li, Zhonglian,Zhang, Zhiguo,Zhang, Wei,Liu, Qingfeng,Liu, Tongxin,Zhang, Guisheng
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supporting information
p. 2735 - 2739
(2014/01/06)
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- Copper-catalyzed synthesis of 1,2,4-triazoles via sequential coupling and aerobic oxidative dehydrogenation of amidines
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A convenient, efficient, and practical copper-catalyzed one-pot method for the synthesis of 1,2,4-triazoles has been developed via reactions of amidines. The procedure underwent sequential base-promoted intermolecular coupling (nucleophilic substitution) between two amidines and intramolecular aerobic oxidative dehydrogenation, and the inexpensive, convenient, and efficient method for the synthesis of 1,2,4-triazoles will attract much attention in academic and industrial research. Georg Thieme Verlag Stuttgart · New York.
- Xu, Hao,Jiang, Yuyang,Fu, Hua
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supporting information
p. 125 - 129
(2013/02/23)
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- TRIAZOLIUM AND IMIDAZOLIUM SALTS AND USES THEREOF
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The present disclosure relates to certain new and known triazolium and/or imidazolium salts and to their therapeutic use, for example in methods of treating or preventing an infection by a Plasmodium or Babesia parasite in a subject in need thereof. The triazolium and imidazolium salts are compounds of the Formula (I) or (II): wherein R1-R4, R1′-R3′, R8-R11, X, X′, X″, Y, Y′ and Y″ are as defined in the disclosure.
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Page/Page column 27
(2011/10/31)
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- Anti-Plasmodium activity of imidazolium and triazolium salts
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We have previously reported that tetrazolium salts were both potent and specific inhibitors of Plasmodium replication, and that they appear to interact with a parasite component that is both essential and conserved. The use of tetrazolium salts in vivo is limited by the potential reduction of the tetrazolium ring to form an inactive, neutral acyclic formazan. To address this issue imidazolium and triazolium salts were synthesized and evaluated as Plasmodium inhibitors. Many of the imidazolium and triazolium salts were highly potent with active concentrations in the nanomolar range in Plasmodium falciparum cultures, and specific to Plasmodium with highly favorable therapeutic ratios. The results corroborate our hypothesis that an electron-deficient core is required so that the compound may thereby interact with a negatively charged moiety on the parasite merozoite; the side groups in the compound then form favorable interactions with adjacent parasite components and thereby determine both the potency and selectivity of the compound.
- Vlahakis, Jason Z.,Lazar, Carmen,Crandall, Ian E.,Szarek, Walter A.
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experimental part
p. 6184 - 6196
(2010/09/14)
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- A novel method for the synthesis of 3,5-disubstituted-(NH)-1,2,4-triazoles from 3,6-diaryl-1,2,4,5-tetrazines
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The reaction of 3,6-diaryl-1,2,4,5-tetrazines and 2-aryl substituted acetonitriles, under basic conditions, leads unexpectedly to 3,5-diaryl-(NH)-1,2,4-triazoles in moderate yields. A mechanism is proposed.
- Haddadin, Makhluf J.,Ghazvini Zadeh, Ebrahim H.
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experimental part
p. 1654 - 1656
(2010/05/19)
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- Facile synthesis of 1,2,4-triazoles via a copper-catalyzed tandem addition-oxidative cyclization
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A simple one-step synthesis of 1,2,4-triazole derivatives is provided by a copper-catalyzed oxidative coupling reaction under an atmosphere of air. The process should consist of sequential N-C and N-N bond-forming copper-catalyzed oxidative coupling reactions. Starting materials and the copper catalyst are readily available and inexpensive. A wide range of functional groups are tolerated to achieve chemical diversity.
- Ueda, Satoshi,Nagasawa, Hideko
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supporting information; experimental part
p. 15080 - 15081
(2010/01/16)
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- A ceric ammonium nitrate N-dearylation of N-p-anisylazoles applied to pyrazole, triazole, tetrazole, and pentazole rings: Release of parent azoles. Generation of unstable pentazole, HN5/N5-, in solution
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(Chemical Equation Presented) The reaction of cerium(IV) ammonium nitrate (CAN) with a range of N-(p-anisyl)azoles in acetonitrile or methanol solvents leads to N-dearylation releasing the parent NH-azole and p-benzoquinone in comparable yields. The scope and limitations of the reaction are explored. It was successful with 1-(p-anisyl)pyrazoles, 2-(p-anisyl)-1,2,3-triazoles, 2-(p-anisyl)-2H-tetrazoles, and 1-(p-anisyl)pentazole. The dearylation renders the p-anisyl group as a potentially useful N-protecting group in azole chemistry. The azole released in solution from 1-(p-anisyl)pentazole is unstable HN5, the long-sought parent pentazolic acid. p-Anisylpentazole samples were synthesized with combinations of one, two, and three 15N atoms at all positions of the pentazole ring. The unstable HN 5/N5- produced at -40°C did not build up in the solution but degraded to azide ion and nitrogen gas with a short lifetime. The 15N-labeling of the N3- ion obtained from all samples proved unequivocally that it came from the degradation of HN 5 (tautomeric forms) and/or its anion N5- in the solution.
- Butler, Richard N.,Hanniffy, John M.,Stephens, John C.,Burke, Luke A.
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p. 1354 - 1364
(2008/04/12)
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- Microwave-promoted rhodium-catalyzed arylation of heterocycles through C-H bond activation
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Performance-enhancing ligands: Two new bridged bicyclic phosphines 1a,b based on the "phoban" skeleton (see structures of their naphth-2-ylmethyl bromide salts; P yellow, Br brown, C white) are central to a practical catalytic method for the direct arylation of a variety of nitrogen heterocycles using aryl bromides. Broad functional-group tolerance was observed, and the use of microwave radiation allowed for short reaction times. (Chemical Equation Presented)
- Lewis, Jared C.,Wu, Jessica Y.,Bergman, Robert G.,Ellman, Jonathan A.
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p. 1589 - 1591
(2008/02/01)
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- An improved procedure for the deamination of symmetrical 3,5-disubstituted 4-amino-1,2,4-triazoles
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A number of symmetrical 3,5-disubstituted-4H-1,2,4-triazoles have been synthesized in good yields by deamination of the corresponding 4-amino-1,2,4-triazoles via reductive diazotation of these amino compounds in the presence of hypophosphorous acid. Analy
- Bentiss, Fouad,Lagrenee, Michel,Vezin, Herve,Bouanis, Marya,Mernari, Bouchaib
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- An alternative channel of reductive condensation of trichloromethylarenes with hydrazines
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The reductive condensation of trichloromethylarenes with hydrazines can proceed without intermediate formation of pyridinium salts and without participation of pyridine in the reduction act. Variants of reductive condensation using hydrazines as reducting agents and α-chlorobenzylhydrazines and hydrazonoyl chlorides, nitrite imines, or hydrazonoylpyridinium salts as intermediates are considered. α-Chlorobenzylhydrazines and hydrazonoyl chlorides are shown to be the most probable intermediates.
- Belen'kii,Luiksaar,Chuvylkin,Krayushkin
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p. 886 - 893
(2007/10/03)
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- Thermolysis of triazoles as melts - Is the 3,5-diphenyl-1,2,4-triazole group a good leaving group?
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The mechanism of the rearrangement of 4-alkyltriazoles to the corresponding 1-alkyltriazoles on thermolysis at 330 °C is shown to involve initial formation of an intermediate 1,4-dialkyltriazolium triazolate salt. The triazolate ion subsequently attacks at the alkyl group bearing 1- and 4-positions of the dialkyltriazolium ion, yielding the observed products. No evidence for unimolecular reaction steps has been found. The triazole moiety in these compounds is only a weak leaving group, which requires activation by alkylation. Unimolecular reaction steps never take place, neither from neutral triazole species nor from activated dialkyl-substituted triazolium species.
- Gautun, Odd R.,Carlsen, Per H. J.
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p. 3749 - 3753
(2007/10/03)
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- Photochemistry of N-heterocycles. 7: Light induced reductive ring contractions of sixmembered cyclic iminium ions
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Photochemically induced reductive ring contractions, previously observed for 2,5-dihydro-1,2,4-triazines, have also been verified for 1,4-dihydropyrimidines 2a,b, the dihydro-1,2,4,5-tetrazine 9, and dihydro-1,3,5-triazines 11a,b giving rise to fivemembered fully unsaturated heterocycles (pyrroles 4a,b, imidazoles 13a,b, and triazole 10, respectively). The 1,4-dihydropyrazines 15a-j tend to decompose in acidified 2-propanol in the dark, but on irradiation they also undergo reductive ring contraction furnishing solely the 1,2,5-triarylpyrroles 16a-d rather than the (a priori also possible) isomeric 1,3,4-triarylpyrroles 17a-d. In contrast, the 3,6-diphenylpyrid-azine 18 gives the 4-isopropyl-analogue 19 in low yield upon irradiation in hydrogen chloride saturated 2-propanol. Wiley-VCH Verlag GmbH, 2000.
- Nagy, Jozsef,Madarasz, Zoltan,Rapp, Rudolf,Szoelloesy, Aron,Nyitrai, Jozsef,Doepp, Dietrich
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p. 281 - 290
(2007/10/03)
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- Thermolysis of N-Allylic 1,2,4-Triazoles
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A number of 4-allylic substituted 3,5-diphenyl-4H-1,2,4-triazoles were thennolyzed at 315-320° in evacuated glass ampoules. The main reaction in the melt was rearrangement to the corresponding 1-substituted triazoles, which appeared to proceed via competing SN2 and SN2′ mechanisms. The allylic systems were observed to undergo [2,3]-allyl walk reactions between the 1- and 2-ring positions. Allyl to vinyl isomerization also took place. Substitution of the allylic moiety increased the rate of reaction but decreased the rate of isomerization of allylic to the vinylic substituted triazoles. The 4-vinyl substituted triazoles were inert under the reaction conditions. Some triazoles were converted into substituted pyridines. This was proposed to proceed via nitrogen extrusion and formation of a 1,3-dipolar intermediate (nitrile ylide) which added intramolecularly to the allyl moiety and subsequently aromatized to the pyridine.
- Carlsen, Per H. J.,Jorgensen, Kare B.
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p. 797 - 806
(2007/10/03)
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- Photoinduced molecular rearrangements. The photochemistry of some 1,2,4-oxadiazoles in the presence of nitrogen nucleophiles. Formation of 1,2,4-triazoles, indazoles, and benzimidazoles
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The photochemistry of some 3,5-disubstituted 1,2,4-oxadiazoles in the presence of nitrogen nucleophiles [external, such as added amines or hydrazines, or internal, such as an o-aminophenyl moiety at C(3) of the oxadiazole ring] has been investigated. In the irradiation of 5-amino-(or 5-N-substituted amino) 3-phenyl-1,2,4-oxadiazoles in the presence of aliphatic primary amines (or ammonia), photolytic species arising from heterolytic cleavage of the ring O-N bond capture the nucleophilic reagent to give open-chain intermediates, which develop into 1,2,4-triazolin-5-ones. Similarly, irradiations of 3,5-diphenyl-, 3-methoxy-5-phenyl-, and 5-methyl-3-phenyl-1,2,4-oxadiazoles gave 1,2,4-triazoles. In the same context, irradiations of representative substrates in the presence of hydrazines have been also investigated. In the irradiation of 3-(o-aminophenyl)-5-methyl-, 3-[o-(methylamino)phenyl]-5-methyl-, and 3-(o-aminophenyl)-5-phenyl-1,2,4-oxadiazoles, concomitant formation of indazoles and benzimidazoles, presumably arising from a common photolytic species, has been observed. Some mechanistic aspects have been considered, and possible applications in synthesis have been pointed out.
- Buscemi, Silvestre,Vivona, Nicolo,Caronna, Tullio
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p. 8397 - 8401
(2007/10/03)
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- Synthesis of N-Substituted Oxo- and Thioxopyrimidines from 1,2,4-Dithiazolium Salts
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2,4-Diaryl-substituted 1,3-thiazine-5-carbonitriles 5, 6, obtained by reaction of 1,2,4-dithiazolium salts 1 with activated cyanoacetates, undergo ring transformations in the presence of primary and secondary amines.Thus, 5 and 6 react with primary amines under mild conditions to give hardly accessible N-3-substituted oxopyrimidine- or thioxopyrimidine-5-carbonitriles 11, 16, with secondary amines to give N-3-unsubstituted pyrimidine derivatives 14, 19 and with diamines to give imidazopyrimidines or pyrimidopyrimidines 23a, b.After alkylation of 1,3-thiazines 6, highly reactive 1,3-thiazinium salts 8 can be isolated. - Key Words: 1,3-Thiazines / Pyrimidines / Thiazinium salts
- Holzer, Max,Dobner, Bodo,Briel, Detlef
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p. 895 - 900
(2007/10/02)
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- Substituent Effects in the Rearrangement of 4-Alkyl-4H-1,2,4-triazoles
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A study of the thermal rearrangement of neat 4-alkyl-substituted 4H-1,2,4-triazoles to the corresponding 1-alkyl-1H-1,2,4-triazoles showed that the rearrangement was accompanied by formation of 3,5-diphenyl-1H-1,2,4-triazole and alkenes.The composition of
- Gautun, Odd Reidar,Carlsen, Per H. J.
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p. 411 - 416
(2007/10/02)
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- SYNTHESIS OF NITROGEN HETEROCYCLES FROM 1-METHYLTHIO-2-PHENYL-2-AZABUTA-1,3-DIENE-4,4-DICARBONITRILES
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The reactions of title compounds with different nucleophiles afforded a simple method for a synthesis of pyrimidines, 1,2,4-triazoles, 1,2,4-oxadiazoles and 1,3,5-triazines.
- Lorente, Antonio,Gamez, Pedro,Mar Contreras, Maria del
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p. 113 - 124
(2007/10/02)
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- Synthesis of Bis(α-alkylaminobenzylidene)hydrazines and their Transformation into 4-Alkyl-4H-1,2,4-triazoles
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Sterically hindered 4-alkyl-3,5-diphenyl-4H-1,2,4-triazoles have been prepared by reacting bis(α-chlorobenzylidene)hydrazine with alkylamines.Under mild conditions this reaction gives, as intermediates, bis(α-alkylaminobenzylidene)hydrazines, a new class of compound.The stability of these compounds appeared to increase with increasing bulk of the alkyl substituent.Upon being heated the compounds, either neat or in a variety of solvents, were transformed into the corresponding triazoles in high yields.Bis(α-alkylaminobenzylidene)hydrazines with sterically bulky groups, e.g. tert-butyl or 1-adamantyl, undergo cyclization in conjuction with elimination to form, as the major product, 3,5-diphenyl-1H-1,2,4-triazole.
- Gautun, Odd Reidar,Carlsen, Per H. J.
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p. 609 - 615
(2007/10/02)
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- On the Mechanism of the Thermal Rearrangement of 4-Alkyl-4H-1,2,4-Triazoles. Synthesis and Reaction of Optically Active Triazoles
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In order to elucidate the mechanism of the thermal rearrangement of 4-alkyl-substituted 4H-1,2,4-triazoles to the corresponding 1-alkyl-1H-1,2,4-triazoles, the behaviour of 4--3,5-diphenyl-4H-1,2,4-triazole has been studied.The thermal rearra
- Carlsen, Per H. J.,Gautun, Odd Reidar
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p. 485 - 488
(2007/10/02)
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- Preparation and reactions of 5-Aryl-1,4,2-dithiazolium salts
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S-Thioaroylsulfenamides (ArCSSNH2), formed by reaction of ArCSS-Na+ with hydroxylamine-O-sulfonic acid, were aroylated or acylated to give N-aroyl- or N-acyl-S-thioaroylsulfenamides, respectively, which were then cyclized with dehydration to afford 3-substituted 5-aryl-1,4,2-dithiazolium salts. The behavior of 3,5-diphenyl-1,4,2-dithiazolium Perchlorate toward nucleophiles such as active methylene and amino compounds was studied systematically. The reaction can be classified into two cases depending on fission modes of initial adducts, i.e., ring opening-ring closure reaction (Path B) and fragmentation of dithiazole ring (Path C), and in some cases the initial adducts were isolated.
- Yonemoto, Katsumi,Shibuya, Isao,Tsuchiya, Tohru,Masahiko Yasumoto,Taguchi, Yoichi
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p. 2933 - 2937
(2007/10/02)
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- The Configuration of 1,2-Diketone Hydrazone Oximes
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The configuration of 1,2-diketone (Z)-hydrazone (E)-oximes 3a-c was determined by ring closure with formaldehyde to 1,2,4-triazine 4-oxides 5a-c and the tautomeric 4-hydroxy-1,2,4-triazines 6a-c and by Beckmann reaction to 1,2,4 triazoles 8a-c.From benzil
- Gnichtel, Horst,Toepper, Bernhard
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p. 1071 - 1074
(2007/10/02)
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- A potassium amide induced ring transformation of 1,2,4-triazines into 1,2,4-triazoles and 1,3,5-triazines
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5-Phenyl- and 3,5-diphenyl-1,2,4-triazine, when treated with potassium amide in liquid ammonia, are converted into a mixture of phenyl derivatives of 1,2,4-triazole and amino-1,3,5-triazines. The ring contraction of the 1,2,4-triazine ring into the 1,2,4-triazole ring has been explained by an initial addition of the amide ion to C-6, ring opening by fission of the N1-C6 bond and ring closure (ANRORC-mechanism). The transformation of the 1,2,4-triazine ring into the 1,3,5-triazine ring has been studied by means of 15N-labeled potassium amide. It was found that the nitrogen of the amide ion becomes one of the ring nitrogen atoms in the 1,3,5-triazine ring and that the exocyclic amino group is imlabeled. Based on these 15N-labeling studies, it is proposed that this ring transformation starts with an initial addition of the amide ion to C-5, ring opening between C-5 and C-6, a dehydrogenative rearrangement of the open-chain intermediate 1-amino-2,4,5-triazahexatriene into 1-amino-4-cyano-2,4-diaza-1,3-butadiene, and ring closure.
- Rykowski,Van Der Plas
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