- UV-Induced 1,3,4-Oxadiazole Formation from 5-Substituted Tetrazoles and Carboxylic Acids in Flow
-
A range of 1,3,4-oxadiazoles have been synthesized using a UV-B activated flow approach starting from carboxylic acids and 5-substituted tetrazoles. The application of UV light represents an attractive alternative to the traditional thermolytic approach and has demonstrated comparable efficiency and versatility, with a diverse substrate scope, including the incorporation of highly substituted amino acids.
- Green, Luke,Livingstone, Keith,Bertrand, Sophie,Peace, Simon,Jamieson, Craig
-
supporting information
p. 14866 - 14870
(2020/11/11)
-
- Experimental and Theoretical Studies on the Mechanism of DDQ-Mediated Oxidative Cyclization of N-Aroylhydrazones
-
The controversial single-electron-transfer process, frequently proposed in many 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)-mediated reactions, was investigated experimentally and theoretically using the oxidative cyclization of aroylhydrazone with DDQ. DDQ-mediated oxadiazole formation involves several processes, including cyclization to form an oxadiazole ring and N-H bond cleavage, either by proton, hydride, or hydrogen atom transfer. The detailed mechanistic study using the M06-2X density functional theory, and the 6-31+G(d,p) basis set, suggests that the pathways involving radical ion pair (RIP) intermediates, which resulted from single-electron transfer (SET), were found to be energetically nearly identical to the pathway without the SET. The substituent-dependent reactivity of oxadiazole formation was consistent with the free energy profiles of both pathways, with or without the SET. This result indicates that in addition to the electron-transfer pathway, the nucleophilic addition/elimination pathway for DDQ should be considered as a possible mechanism of the oxidative transformation reaction using DDQ.
- Baek, Jihye,Je, Eun-Kyung,Kim, Jina,Qi, Ai,Ahn, Kwang-Hyun,Kim, Yongho
-
p. 9727 - 9736
(2020/10/02)
-
- One pot solvent-free solid state synthesis, photophysical properties and crystal structure of substituted azole derivatives
-
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
-
p. 315 - 325
(2019/05/27)
-
- Synthesis method of 2,5-disubstituted-1,3,4-oxadiazole
-
The invention discloses a synthesis method of a drug intermediate, namely, 2,5-disubstituted-1,3,4-oxadiazole. 2,5-disubstituted-1,3,4-oxadiazole is synthesized with a one-pot method under the photocatalytic action with simple hydrazide compounds as raw materials. 2,5-disubstituted-1,3,4-oxadiazole can be produced through a reaction at the room temperature with a common halogen lamp as a light source, eosinY as a catalyst, potassium carbonate as an additive and ethanol as a solvent. The method has the characteristics that the raw material source is simple, the reaction condition is mild and the like.
- -
-
Paragraph 0007; 0028
(2018/08/04)
-
- Synthesis, liquid-crystalline, photophysical and chemosensor properties of oxadiazole/thiadiazole-based amphiphiles with glycerol groups
-
Two series of heterocycle-based mesogens consisting of a long 2,5-diphenyl-1,3,4-oxadiazole/thiadiazole rigid core with three lipophilic and flexible alkyl chains at one end and a polar glycerol group at the opposite end have been synthesized via one pot cyclization reaction. These compounds were investigated by polarizing optical microscopy (POM), differential scanning calorimetry (DSC), X-ray scattering, cyclic voltammetry, UV–vis spectroscopy and photoluminescence measurements. Upon elongation of the alkyl chains, a transition from hexagonal columnar phase to Pm3ˉn-type cubic phase was observed in both series. Oxadiazole series are blue luminescent LCs with binding selectivity to Li+, while thiadiazole series are blue-green luminescent LCs with binding selectivity to Fe3+.
- Xiao, Yulong,Gao, Hongfei,Wang, Tingyan,Zhang, Ruilin,Cheng, Xiaohong
-
p. 360 - 367
(2017/09/18)
-
- Reagent/Substituent Switching Approach for the Synthesis of Substituted 1,3,4-Oxadiazole/1,3,4-Oxadiazoline and 1,2,4-Triazole Derivatives from N-Substituted Hydrazides
-
A metal-free method for the synthesis of substituted 1,3,4-oxadiazole/1,3,4-oxadiazoline and 1,2,4-triazole derivatives from a common starting material via reagent/substituent switching is reported. In the presence of 2-fluoropyridine/triflic anhydride, 1,3,4-oxadiazole derivatives were exclusively formed from N′-tert-butylhydrazides and 1,3,4-oxadiazoline derivatives were produced from N-phenylhydrazides. On the other hand, when using pyridine/triflic anhydride, salts of 1,2,4-triazoles were the sole products. (Figure presented.).
- Kotipalli, Trimurtulu,Kavala, Veerababurao,Konala, Ashok,Janreddy, Donala,Kuo, Chu-Wei,Yao, Ching-Fa
-
p. 2652 - 2660
(2016/09/03)
-
- The effects of asymmetric bent-shaped compounds on the temperature range and electro-optical performances of liquid crystalline blue phases
-
A series of asymmetric and symmetric bent-shaped molecules with branched terminals were synthesized and characterized. Their effects on inducing blue phase and electro-optical performances were compared and analyzed experimentally. It was found that the asymmetric and symmetric compounds almost have the same effect on inducing and stabilizing blue phase, but the electro-optical performance of mixtures doped with asymmetric compounds are much better than that of mixtures doped with symmetric compounds for they have a totally different dielectric anisotropy which can contribute to a larger Kerr constant.
- Wang, Xin,He, Wan-Li,Yang, Zhou,Wang, Dong,Cao, Hui,Zheng, Zhi-Gang,Liu, Zhen,Liu, Xiang
-
p. 110750 - 110757
(2016/12/07)
-
- Palladium-Catalyzed Aminocarbonylation Reaction to Access 1,3,4-Oxadiazoles using Chloroform as the Carbon Monoxide Source
-
A palladium-catalyzed aminocarbonylation reaction of aryl halides with chloroform and tetrazoles has been developed, where chloroform was employed as the carbon monoxide (CO) source in the presence of cesium hydroxide. The in situ generated N-acylated tetrazoles were unstable and easily decomposed to afford 2,5-disubstituted 1,3,4-oxadiazoles. A wide range of tetrazoles and aryl halides reacted smoothly under the optimized reaction conditions to give the corresponding products in moderate to good yields.
- Li, Zhengyi,Wang, Liang
-
p. 3469 - 3473
(2016/01/25)
-
- One-Pot Synthesis of 2,5-Diaryl 1,3,4-Oxadiazoles via Di-tert-butyl Peroxide Promoted N-Acylation of Aryl Tetrazoles with Aldehydes
-
A metal- and base-free protocol for one-pot synthesis of 2,5-diaryl 1,3,4-oxadiazoles via a radical-promoted cross-dehydrogenative coupling strategy was developed. This reaction involved the N-acylation of aryl tetrazoles with aryl aldehydes, followed by thermal rearrangement. A wide range of aryl tetrazoles and aryl aldehydes survived the reaction conditions to deliver the corresponding products in moderate to good yields. (Chemical Equation Presented).
- Wang, Liang,Cao, Jing,Chen, Qun,He, Mingyang
-
supporting information
p. 4743 - 4748
(2015/05/13)
-
- Metal-Free Synthesis of 1,3,4-Oxadiazoles from N′-(Arylmethyl)hydrazides or 1-(Arylmethyl)-2-(arylmethylene)hydrazines
-
An efficient and versatile metal-free synthesis of 1,3,4-oxadiazoles from N′-(arylmethyl)hydrazides or 1-(arylmethyl)-2-(arylmethylene)hydrazines through oxidative dehydrogenation is reported. A range of 2,5-disubstituted 1,3,4-oxadiazoles were prepared by treating N′-(arylmethyl)hydrazides with (diacetoxyiodo)benzene in acetonitrile or by treating 1-(arylmethyl)-2-(arylmethylene)hydrazines with [bis(trifluoroacetoxy)iodo]benzene in methyl tert-butyl ether. Aldehyde N-acylhydrazones and aldazines were initially generated in situ as intermediates.
- Shang, Zhenhua,Chu, Qianqian,Tan, Sheng
-
p. 1032 - 1040
(2015/03/30)
-
- Symmetrical and non-symmetrical 2,5-diaryl-1,3,4-oxadiazoles: Synthesis and photophysical properties
-
We report herein the synthesis of 2,5-diaryl-1,3,4-oxadiazoles containing both electron-donating and withdrawing substituents as well as bis- and tris-2,5-disubstituted-1,3,4-oxadiazoles containing electron-donating substituents. The photophysical properties of the synthesized compounds were studied using UV-Vis and fluorescence spectroscopy. The aryl substitution pattern was found to have a marked impact on both luminescence efficiency and other photophysical properties. An increase in the number of electron-donating groups and/or the number of heterocyclic rings provided a red shift of the emission maxima, as well as an increase of the Stokes shifts. The same effect was observed for mono-1,3,4-oxadiazoles containing push-pull substituents on the aryl rings.
- Paraschivescu, Codru?a C.,H?dade, Niculina D.,Coman, Anca G.,Gautier, Arnaud,Cisnetti, Federico,Matache, Mihaela
-
p. 3961 - 3964
(2015/06/08)
-
- In situ generated cetyltrimethylammonium bisulphate in choline chloride-urea deep eutectic solvent: A novel catalytic system for one pot synthesis of 1,3,4-oxadiazole
-
Cetyltrimethylammonium bisulphate ([CTA]HSO4) catalysed one pot synthesis of 2,5-disubstituted-1,3,4-oxadiazoles from carboxylic acid and acid hydrazide in biodegradable deep eutectic solvent is investigated. [CTA]HSO 4 is generated in situ from cetyltrimethylammonium peroxodisulphate. Cyclization of diacylhydrazide using [CTA]HSO4 gives best alternative to traditional dehydration agents. Its remarkable features include a milder procedure, simplicity in workup and purification, good to excellent yields of products, use of inexpensive, recyclable reagents, and eco-friendly aspects by avoiding toxic catalysts/reagents and solvents. Graphical Abstract: [Figure not available: see fulltext.].
- More, Priyanka Anant,Gadilohar, Balu Laxman,Shankarling, Ganapati Subray
-
p. 1393 - 1398
(2014/08/18)
-
- Electrochemical oxidation of aldehyde-N-arylhydrazones into symmetrical-2,5-disubstituted-1,3,4-oxadiazoles
-
A convenient, efficient and one-pot synthesis of chemically and pharmaceutically interesting symmetrical-2,5-disubstituted-1,3,4-oxadiazoles is reported. The protocol involves anodic oxidation of aldehyde-N-arylhydrazones in anhyd. MeCN-LiClO4. Constant potential electrolysis carried out in an undivided cell and platinum electrodes leads to the formation of the corresponding oxadiazoles under ambient condition and the mechanism was deduced from voltammetry studies. The reaction proceeded smoothly with high atom economy. Springer Science+Business Media Dordrecht 2013.
- Singh, Sushma,Sharma, Laxmi K.,Saraswat, Apoorv,Siddiqui, Ibadur R.,Singh, Rana K. Pal
-
p. 947 - 960
(2014/05/06)
-
- Electrosynthesis and screening of novel 1,3,4-oxadiazoles as potent and selective antifungal agents
-
The electrochemical oxidation of aldehyde-N-aroylhydrazone has been studied in the presence of NaClO4 as supporting electrolyte in MeOH solution using cyclic voltammetry and controlled potential electrolysis. The results indicate that intramolecular cyclization of aldehyde-N-aroylhydrazone has been successfully performed at a platinum electrode in an undivided cell with good yields of the corresponding 1,3,4-oxadiazoles at ambient conditions. The reaction products were characterized by spectroscopic methods and a mechanism was deduced from voltammetry studies. The antifungal activity of the synthesized compounds was evaluated on Fusarium oxysporum, Alternaria solani, Candida albicans and Aspergillus niger. The results revealed that all the synthesized compounds have significant antifungal activity against the tested fungi. Among the synthesized derivatives 7b, 7d, 7g, 7h, 7i, 7j and 7r were found to be the most effective antifungal compounds. The Royal Society of Chemistry 2013.
- Singh, Sushma,Sharma, Laxmi Kant,Saraswat, Apoorv,Siddiqui, Ibadur R.,Kehri, Harbans K.,Singh, Rana K. Pal
-
p. 4237 - 4245
(2013/05/08)
-
- Efficient oxidative cyclization of N -acylhydrazones for the synthesis of 2,5-disubstituted 1,3,4-oxadiazoles using t-BuOI under neutral conditions
-
An efficient procedure for the oxidative cyclization of N -acylhydrazones was developed utilizing tert-butyl hypoiodite (t-BuOI), which is generated in situ from t -BuOCl and NaI. A variety of 2,5-disubstituted 1,3,4-oxadiazoles were synthesized in high yields within short reaction time. The method is also suitable for cyclization of N -acylhydrazones derived from heterocyclic aldehydes and aliphatic aldehydes. Mild reaction conditions and simple workup operations make the procedure a good alternative for the synthesis of 2,5-disubstituted 1,3,4-oxadiazoles.
- Gao, Peng,Wei, Yunyang
-
p. 113 - 119
(2013/05/23)
-
- Efficient oxidative cyclisation of acid hydrazides to 2,5-disubstituted 1,3,4-oxadiazoles catalysed by Bu4NI with t-BuOOH as oxidant
-
Acid hydrazides or araldehyde N-acylhydrazones can be converted in good yields to, respectively, symmetrical or unsymmetrical, 2,5-disubstituted 1,3,4-oxadiazoles at 60 °C by a Bu4NI-catalysed procedure which requires the presence of a base and 2.5 equiv. of t-butyl hydroperoxide.
- Gao, Peng,Wei, Yunyang
-
p. 506 - 510
(2013/09/12)
-
- Hockey stick liquid crystals based on a 2,5-asymmetric disubstituted [1,3,4]oxadiazole core
-
The article describes the liquid-crystalline properties of some 2,5-asymmetric disubstituted [1,3,4]oxadiazole derivatives containing an azo and an ester linkage obtained through esterification of 2-(4-methoxyphenyl)-5-(4- hydroxyphenyl)-[1,3,4]oxadiazole with a series of 4-(4-alkoxyphenyl)-benzoic acids containing 6-10 and 18 aliphatic carbon atoms. All reported compounds present liquid-crystalline properties, evidenced by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM), with nematic and smectic C type structures, with very large range of stability of mesophases (between 130°C and 198°C on heating and 134°C and 214°C on cooling). Copyright Taylor & Francis Group, LLC.
- Cioanca, Elena-Raluca,Elena, Luiza Epure,Carlescu, Irina,Lisa, Gabriela,Wilson, Daniela,Hurduc, Nicolae,Scutaru, Dan
-
experimental part
p. 51 - 63
(2012/05/05)
-
- 17O NMR studies of substituted 1,3,4-oxadiazoles
-
Three series of substituted 1,3,4-oxadiazoles were studied by 17O NMR spectroscopy. Chemical shifts values were correlated with empirical Hammett parameters as well as calculated bond lengths and chemical shielding values.
- Gierczyk, Blazej,Zalas, MacIej,Kazmierczak, Marcin,Grajewski, Jakub,Pankiewicz, Radoslaw,Wyrzykiewicz, Bozena
-
experimental part
p. 648 - 654
(2012/01/06)
-
- Cu(II) catalyzed imine C-H functionalization leading to synthesis of 2,5-substituted 1,3,4-oxadiazoles
-
A direct access to symmetrical and unsymmetrical 2,5-disubstituted [1,3,4]-oxadiazoles has been accomplished through an imine C-H functionalization of N-arylidenearoylhydrazide using a catalytic quantity of Cu(OTf)2. This is the first example of amidic oxygen functioning as a nucleophile in a Cu-catalyzed oxidative coupling of an imine C-H bond. These reactions can be performed in air atmosphere and moisture making it exceptionally practical for application in organic synthesis.
- Guin, Srimanta,Ghosh, Tuhin,Rout, Saroj Kumar,Banerjee, Arghya,Patel, Bhisma K.
-
p. 5976 - 5979
(2012/01/02)
-
- N-chlorosuccinimide/1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)-mediated synthesis of 2,5-disubstituted 1,3,4-oxadiazoles
-
A mixture of N-chlorosuccinimide and 1,8-diazabicyclo[5.4.0]undec-7-ene oxidatively cyclizes structurally diverse acyl hydrazone, thereby providing an efficient and convenient method for the synthesis of various 2,5-disubstituted 1,3,4-oxadiazoles. The salient features of this method are mild reaction conditions, short reaction time, excellent yields, and simple workup procedure. Copyright
- Pardeshi, Santosh P.,Patil, Sachin S.,Bobade, Vivek D.
-
experimental part
p. 1601 - 1606
(2010/06/20)
-
- Copper-mediated direct arylation of 1,3,4-oxadiazoles and 1,2,4-triazoles with aryl iodides
-
The copper-mediated direct arylation of 1,3,4-oxadiazoles and 1,2,4-triazoles with aryl iodides proceeds efficiently in the presence of suitable ligands and bases. This method allows the installation of a variety of aryl moieties bearing a functional group such as ketone, ester, or nitrile so as to enable the facile construction of various functionalized oxadiazole and triazole core π systems.
- Kawano, Tsuyoshi,Yoshizumi, Tomoki,Hirano, Koji,Satoh, Tetsuya,Miura, Masahiro
-
supporting information; experimental part
p. 3072 - 3075
(2009/12/06)
-
- Trichloroisocyanuric acid-mediated one-pot synthesis of unsymmetrical 2,5-disubstituted 1,3,4-oxadiazoles at ambient temperature
-
An efficient method for the one-pot synthesis of unsymmetrical 2,5-disubstituted 1,3,4-oxadiazoles has been developed using trichloroisocyanuric acid (TCCA) at ambient temperature. A wide variety of aromatic as well as heterocyclic aldehydes exhibit condensation with a variety of acylhydrazines followed by oxidative cyclization to yield corresponding unsymmetrical 2,5-disubstituted 1,3,4-oxadiazoles. The mild nature of the synthesis and short reaction time are notable advantages of the developed protocol. Copyright Taylor & Francis Group, LLC.
- Pore,Mahadik,Desai
-
p. 3121 - 3128
(2008/12/22)
-
- Bent-core systems based on [1,3,4]oxadiazole core with shape biaxiality
-
The present paper is presenting the Synthesis and characterization of new [1,3,4]oxadiazole derivatives obtained by attaching different mesogenic units to the central core. Liquid crystals properties analysis by POM and DSC techniques is presented and structure-properties correlations are discussed.
- Apreutesei, Daniela,Mehl, Georg H.
-
experimental part
p. 527 - 533
(2009/12/24)
-
- Synthesis and properties of iridium complexes based 1,3,4-oxadiazoles derivatives
-
A series of iridium complexes with 2,5-diaryl-[1,3,4]-oxadiazole ligands were synthesized and their electrochemical, photophysical, and electroluminescent (EL) properties studied. It was found that electron-withdrawing or donating substituents on the phenyl ring affected the emission maxima. Complex 3, iridium(III) bis(2,5-bis-(2-hydroxyphenyl)-[1,3,4]oxadiazolato-C2′,N3) (acetyl acetonate), was characterized by single-crystal X-ray structural determination. Three organic light emitting diodes devices were fabricated, which showed stable green-yellow luminescence.
- Xu, Zhaowu,Li, Yang,Ma, Xuemei,Gao, Xindong,Tian, He
-
p. 1860 - 1867
(2008/09/17)
-
- Oxidative cyclization of aromatic aldehyde n-acylhydrazones by bis(trifluoroacetoxy)iodobenzene
-
Aromatic aldehyde N-acylhydrazones were oxidized into 2,5-disubstituted 1,3,4-oxadiazoles with bis(trifluoroacetoxy)iodobenzene in CHCl3 or DMSO at room temperature in good to excellent yields. Copyright Taylor & Francis Group, LLC.
- Shang, Zhenhua
-
p. 2927 - 2937
(2007/10/03)
-
- Oxidative cyclization of aldazines with bis(trifluoroacetoxy)iodobenzene
-
Symmetrical and unsymmetrical aldazines are efficiently converted to 2,5-disubstituted-1,3,4-oxadiazoles by oxidation with bis(trifluoroacetoxy) iodobenzene (BTI).
- Shang, Zhenhua,Reiner, John,Chang, Junbiao,Zhao, Kang
-
p. 2701 - 2704
(2007/10/03)
-
- Zirconium(IV) chloride mediated cyclodehydration of 1,2-diacylhydrazines: A convenient synthesis of 2,5-diaryl 1,3,4-oxadiazoles
-
Zirconium(IV) chloride was invented as a mild catalyst for the cyclodehydration of 1,2-diacylhydrazines. Efficient synthesis of several 2,5-disubstituted 1,3,4-oxadiazoles is reported.
- Sharma,Begum, Asra,Rakesh,Krishna, Palakodety Radha
-
p. 2387 - 2391
(2007/10/03)
-
- Facile synthesis of symmetric and unsymmetric 1,3,4-oxadiazoles using 2-acyl(or aroyl)pyridazin-3-ones
-
Symmetric and unsymmetric 1,3,4-oxadiazoles were synthesized in situ from hydrazine hydrate and the corresponding 2-acyl-4,5-dichloropyridazin-3-ones as acylating agents in polyphosphoric acid or BF3·OEt2 in excellent yields.
- Park, Yong-Dae,Kim, Jeum-Jong,Chung, Hyun-A,Kweon, Deok-Heon,Cho, Su-Dong,Lee, Sang-Gyeong,Yoon, Yong-Jin
-
p. 560 - 564
(2007/10/03)
-
- Rapid synthesis of 2,5-disubstituted 1,3,4-oxadiazoles under microwave irradiation
-
A number of symmetrically 2,5-disubstituted 1,3,4-oxadiazoles are quickly prepared by the reaction of aromatic acids with hydrazine dihydrochloride in a mixture of orthophosphoric acid and phosphorus pentoxide under microwave irradiation.
- Bentiss, Fouad,Lagrenee, Michel,Barbry, Didier
-
p. 935 - 938
(2007/10/03)
-
- A new synthesis of symmetrical 2,5-disubstituted 1,3,4- oxadiazoles
-
Several new 2,5-disubstituted 1,3,4-oxadiazoles have been synthesized in good yields by reaction of aromatic acids with hydrazine dihydrochloride in a mixture of orthophosphoric acid, phosphorus pentoxide and, in general, with addition of phosphorus oxychloride to the reaction mixture. The structures of new oxadiazoles derivatives were confirmed by analytical and spectral data.
- Bentiss, Fouad,Lagrenee, Michel
-
p. 1029 - 1032
(2007/10/03)
-
- Iodobenzene Diacetate Mediated Synthesis of N,N'-Diacylhydrazines: A Convenient Synthesis of 1,3,4-Oxadiazoles
-
Iodobenzene diacetate (IBD) has been found to be an excellent reagent for the oxidation of a variety of acid hydrazides to N,N'-diacylhydrazines which undergo ready cyclization to yield the corresponding oxadiazoles.
- Singh, Shiv P.,Batra, Hitesh,Sharma, Pawan K.
-
p. 468 - 469
(2007/10/03)
-
- Unusual Rearrangement in the Dehydration of Aroylated Butanodihydrazides
-
Dehydration of N,N'-diaroylbutanodihydrazides 3a-f with phosphoryl chloride gave, unexpectedly, 2,5-diaryl-1,3,4-oxadiazoles 4a-f.However, dehydration of N,N'-dialkanoylbutanodihydrazides 1a-c afforded 5,5'-dialkyl-2,2'-(ethandiyl)-bis(1,3,4-oxadiazoles) 2a-c. Key Words: 1,3,4-Oxadiazole / Butanodihydrazides
- Tashtoush, Hasan,Al-Talib, Mahmoud,Odeh, Nedal
-
p. 291 - 292
(2007/10/02)
-
- N,N-Dimethylchlorosulfitemethaniminium chloride as a dehydrating agent - An efficient one-pot synthesis of 1,3,4-oxadiazoles and 4H-3,1-benzoxazin-4-ones
-
Aroylhydrazines (3) on treatment with carboxylic acids (1) in the presence of N,N-dimethylchlorosulfitemethaniminium chloride (2) yields directly 1,3,4-oxadiazoles (4).Reaction between anthranilic acid (6) and carboxylic acids (5) in the presence of 2 affords 4H-3,1-benzoxazin-4-ones (7).
- Sain, Bir,Sandhu, Jagir S
-
p. 768 - 770
(2007/10/02)
-
- Fusion of Aroylhydrazines with Acids - A New Synthesis of 2,5-Diaryl-1,3,4-oxadiazoles
-
Aroylhydrazines and aromatic acids when heated together at 240 deg C for 6 hr yield 2,5-diaryl-1,3,4-oxadiazoles (V) in one step.Permanganate oxidation of 1-aroyl-2-arylidenehydrazines is also shown to be a superior method for preparing 1,3,4-oxadiazoles (V).
- Reddy, P. S. N.,Reddy, P. Pratap
-
p. 890 - 891
(2007/10/02)
-
- Research in the 2,5-Diaryl-1,3,4-oxadiazole Series. 1. Electronic Structures and Spectral-Luminescence Properties of Substituted 2,5-Diphenyl-1,3,4-oxadiazoles
-
The dependence of the spectral-luminescence properties of substituted 2,5-diphenyl-1,3,4-oxadiazoles on the electronic nature of the substituents was studied.Experimental and theoretical studies confirm the electron-acceptor character of the oxadiazole ring and constitute evidence for the rather effective transmission of the electronic effects through the heteroring.
- Popova, N. A.,Yushko, E. G.,Krasovitskii, B. M.,Minkin, V. I.,Lyubarskaya, A. E.,Gol'dberg, M. L.
-
-