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1.
T. R. Hovsepian E. R. Dilanian A. P. Engoyan R. G. Melik-Ohanjanian 《Chemistry of Heterocyclic Compounds》2004,40(9):1194-1198
The cyclization of 4-substituted 1-arylacetyl- and 1-aryloxyacetylthiosemicarbazides and also the potassium salt of (4-bromophenoxy)acetodithiocarbazinic acid in the presence of base gives the novel 3-arylmethyl- and 3-aryloxymethyl-5-mercapto-1,2,4-triazoles and, in the presence of concentrated H2SO4, the novel 5-substituted 2-arylmethyl- and 2-aryloxymethyl-1,3,4-thiadiazoles. 相似文献
2.
4-Methoxylbenzoyl chloride reacting with ammonium thiocyanate and aryloxyacetic acid hydrazides under phase transfer catalysis at room temperature gives 1-aryloxyacetyl-4-(4-methoxylbenzoyl)-thiosemicarbazides (Ia-m). Compounds Ia-m together with glacial acetic acid on exposure to microwave irradiation lead to the formation of 2-(4-methoxylbenzoylamido)-5-aryloxymethyl-1,3,4-thiadiazoles (IIa-m) in excellent yields. 相似文献
3.
Polyethylene glycol (PEG) was found to be an inexpensive, non-toxic, and effective medium for the Michael additions of 3,4-dihydropyrimidines to α,β-ethylenic compounds to provide N3-functionalized dihydropyrimidines in the presence of K2CO3 as the catalyst. Under similar reaction conditions, 2-amino-5-aryloxymethyl-1,3,4-thiadiazoles reacted with methyl acrylate to give unexpected products 5H,6H-[1,3,4]thiadiazolo[1,2-a]pyrimidine-7-ones through tandem Michael addition and intramolecular cyclization. 相似文献
4.
以2-氨基-5-取代苯氧甲基-1,3,4-噻二唑(1)为起始原料, 合成了中间体2-氯乙酰氨基-5-取代苯氧甲基-1,3,4-噻二唑)-2-乙酰亚胺(2)和2-(5-取代苯氧甲基-1,3,4-噻二唑-2-亚胺基)-4-噻唑啉酮(3), 化合物3进一步与取代苯甲醛发生类Knoevenagle缩合反应, 得到了一系列2-(5-取代苯氧甲基-1,3,4-噻二唑-2-亚胺基)-5-(取代苯基亚甲基)-4-噻唑啉酮类化合物4a~4p. 目标化合物4a~4p的结构经IR, 1H NMR和元素分析确证. 相似文献
5.
Diazotization of 2-amino-1,3,4-thiadiazoles gave 1,3,4-thiadiazole-2-diazonium sulfates which were converted to 2-azido-1,3,4-thiadiazoles. The latter reacted with ethyl acetoacetate in the presence of sodium methoxide in methanol to produce 1-(5-R1-1,3,4-thiadiazol-2-yl)-5-R2-1H-1,2,3-triazole-4-carboxylic acid derivatives. The reactions of 2-azido-5-methyl-1,3,4-thiadiazole and 2-azido-1,3-thiazole with ethyl 3-(1,3-benzodioxol-5-yl)-3-oxopropanoate led to the formation of 1,2,3-triazole ring under milder conditions (K2CO3, DMSO). Various 1,2,3-triazole-4-carboxylic acid derivatives were synthesized. 相似文献
6.
7.
Mohamed Al-Omar Omar A. Al-Deeb Hamad A. Al-Khamees Ali A. El-Emam 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2509-2517
Cyclization of 1-(3,4,5-trimethoxybenzoyl)-4-substituted thiosemicarbazides 2a–g with sulphuric acid at ambient temperature afforded the selectively demethylated products 2-(4-hydroxy-3,5-dimethoxyphenyl)-5-substituted amino-1,3,4-thiadiazoles 4a–g. Meanwhile, dehydrative cyclization of 1-(3,4,5-trimethoxybenzoyl)-4-(benzyl or t-butyl)thiosemi- carbazides 2h, i with sulphuric acid yielded 2-(4-hydroxy-3,5-dimetho xyphenyl)-5-amino-1,3,4-thiadiazole 5. On the other hand, dehydration of 2h, i by heating with phosphorus oxychloride yielded 2-(3,4,5-trimethoxyphenyl)-5-amino-1,3,4-thiadiazole 6. 相似文献
8.
Giuseppe Werber Francesco Buccheri Manlio Gentile 《Journal of heterocyclic chemistry》1977,14(7):1263-1265
The ambident nucleophilic behaviour of some 2-amino-5-H-1,3,4-thiadiazoles in alkylation, acylation and nitrosation reaction has been verified. The structures assigned to the 2-amino-1,3,4-thiadiazoles ( 1a-i ) and to the Δ2-1,3,4-thiadiazolines ( 2a-e ) agree with the spectral data. 相似文献
9.
2,5-二取代-1,3,4-噻二唑衍生物的一锅法合成、结构表征及生物活性研究 总被引:4,自引:0,他引:4
采用超声波辐射与相转移催化联用技术, 一锅法合成出了8个新的2-(1-萘乙酰氨基)-5-芳氨甲基-1,3,4-噻二唑化合物, 这种合成方法具有反应条件温和、反应时间较短、产率较高等特点. 新化合物的结构利用IR, 1H NMR, 13C NMR, 1D NOE, MS和元素分析进行了表征. 人环氧酶-2 (COX-2)活性抑制实验结果表明, 目标化合物5f对COX-2具有很强的抑制活性, 抑制率高达95.59%; 化合物5g对COX-2也具有一定的抑制活性. 目标化合物无抗惊厥活性. 相似文献
10.
Novel liquid crystal materials base on amino-thiadiazoles, specifically 5-(3,4-di-, and/or 3,4,5-tri-n-alkoxy)phenyl-2-amino-1,3,4-thiadiazoles (3a–f, n?=?10, 12, 14) and 5-(3,4-di- and/or 3,4,5-tri-n-alkoxy)phenyl-2-(4-amino)phenyl-1,3,4-thiadiazoles (6a–f, n?=?10, 12, 14) were synthesised. The mesomorphic properties of these compounds were studied by differential scanning calorimetry and polarising optical microscopy. All the compounds in series 3a–f and series 6a–f display an enantiotropic columnar phase. The mesomorphic properties were found to be dependent on the number of the side alkoxy chains, and on the length of the rigid core, and on the position of the thiadiazole ring. The best results were obtained with compounds of series 3a–f. 相似文献
11.
《Arabian Journal of Chemistry》2022,15(4):103712
Although recent decades have witnessed the synthesis of 1,3,4-thiadiazoles via phosphorus POCl3-promoted cyclization reaction, simultaneous access to 2-amino-1,3,4-thiadiazole and 2-amino-1,3,4-oxadiazole analogs remains unexpected and elusive. Herein, a detailed regiocontrolled synthesis of 2-amino-1,3,4-thiadiazoles in good to high yields with good regioselectivities from readily available thiosemicarbazides using POCl3 was disclosed. Meantime, to establish a comprehensive structure–activity relationship, 2-amino-1,3,4-oxadiazole derivatives as single regioisomers were prepared via EDCI·HCl-triggered cyclization of the thiosemicarbazide intermediates. The in vitro anti-influenza assays proved that the selected compounds with the pyrazine/pyridine ring exhibited certain inhibitory activities against influenza A virus strains A/HK/68 (H3N2) and A/PR/8/34 (H1N1) in MDCK cells. Among them, N-(adamantan-1-yl)-5-(5-(azepan-1-yl)pyrazin-2-yl)-1,3,4-thiadiazol-2-amine (4j) was the most active compound, and exhibited favorable activity with EC50 values of 3.5 μM and 7.5 μM, respectively. In addition, the molecular docking results explained the reason why compound 4j had dual inhibitory activity and revealed the reasonable binding mode of this compound with the M2-S31N and M2-WT ion channels. This compound had the potential to be further developed as an anti-influenza drug. 相似文献
12.
Equimolar mixtures of aromatic aldehydes with thioglycolic acid and thiosemicarbazide in H2SO4 transform into 2-amino-5-aryl-5H-thiazolo[4,3-b]-1,3,4-thiadiazoles.Translated fromIzvestiya Akademioi Nauk. Seriya Khimicheskaya, No. 3, pp. 763–764, March, 1996. 相似文献
13.
T. V. Shokol V. V. Semenyuchenko V. P. Khilya 《Chemistry of Heterocyclic Compounds》2005,41(5):673-678
By recyclization of 2-R-6-ethyl-7-hydroxy(methoxy)-3-(5-phenyl-1,3,4-thiadiazol-2-yl)chromones when treated with hydrazine hydrate and phenylhydrazine, we synthesized 5-phenyl-2-(3-R-5-R1-1H-pyrazol-4-yl)-1H-1,3,4-thiadiazoles and 2-(3-R-5-R1-1-phenyl-1H-pyrazol-4-yl)-5-phenyl-1H-1,3,4-thiadiazoles. We confirmed the structure of the latter from 1H NMR spectra.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 781–787, May, 2005. 相似文献
14.
5-Substituted 1,3,4-thiadiazol-2(3H)-ones were shown to exist almost exclusively in the oxo tautomeric form with the aid of proton-coupled 15N-NMR spectra using the corresponding 3-methyl-1,3,4-thiadiazol-2(3H)-ones and 5-substituted-2-methoxy-1,3,4-thiadiazoles as reference compounds. 相似文献
15.
A. L. Krasovsky A. M. Moiseev V. G. Nenajdenko E. S. Balenkova 《Chemistry of Heterocyclic Compounds》2002,38(2):231-237
A series of CF3-containing 6,7-dihydro-5H-[1,3,4]thiadiazolo[3,2-a]pyrimidin-7-ols was obtained by the interaction of 2-amino-1,3,4-thiadiazoles with -sulfonylvinyltrifluoromethyldiols and their stereochemistry was established. The structure of 5-(phenylsulfonyl)-7-(trifluoromethyl)-6,7-dihydro-5H-[1,3,4]thiadiazolo[3,2-a]pyrimidin-7-ol was confirmed by X-ray crystallography. 相似文献
16.
Greener and rapid access to bio-active heterocycles: one-pot solvent-free synthesis of 1,3,4-oxadiazoles and 1,3,4-thiadiazoles 总被引:1,自引:0,他引:1
Vivek Polshettiwar 《Tetrahedron letters》2008,49(5):879-883
A novel one-pot solvent-free synthesis of 1,3,4-oxadiazoles and 1,3,4-thiadiazoles by condensation of acid hydrazide and triethyl orthoalkanates under microwave irradiations is reported. This green protocol was catalyzed efficiently by solid supported Nafion®NR50 and phosphorus pentasulfide in alumina (P4S10/Al2O3) with excellent yields. 相似文献
17.
Wen-Long Yang Wen-Li Wang You-Ming Zhang Tai-Bao Wei 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):1770-1777
Abstract Some novel of 5-arylmethylideneamino-1,3,4-thiadiazole-2-ylsulfanyl acetamide derivatives were synthesized by the S-alkylation of 5-arylmethylideneamino-2-mercapto-1,3,4-thiadiazoles with chloroacetyl anilide under solid–liquid phase transfer catalysis using polyethylene glycol-400 (PEG-400) catalyst in the presence of potassium carbonate. Some of the title compounds were investigated for plant growth-regulating activity. They were found to enhance root elongation remarkably at a low concentration. [Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the following free supplemental files: Additional figures and tables]. 相似文献
18.
Heinz Paul Rolf Wessel Günter Huschert 《Monatshefte für Chemie / Chemical Monthly》1981,112(2):209-213
2-Amino-6-aryl-imidazo(2,1-b)-1,3,4-thiadiazoles (1 a-f) were condensed with 1,3-ketocarboxylates e. g. ethyl-butyroacetate, ethyl-benzoylacetate, 4-nitrobenzoylacetate or ethyl-cyclopentanone(2)-carboxylate and ethyl-cyclohexanone(2)-carboxylate directly to imidazo(2,1-b)-1,3,4-thiadiazolo(3,2-a) pyrimidones-(6) (4 a-f, 5 a-f, 6 d, e, 7 a-f, 8 a, d).
11. Mitt. über Heterocyclen; 10. Mitt.Paul, H., Sitte, A., Wessel, R., Arch. Pharm. (Weinheim), im Druck. 相似文献
19.
E. M. Keshk A. A. Abu-Hashem M. M. Girges A. H. Abdel-Rahman F. A. Badria 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1577-1593
Benzo[1,2-b:5,4-b′]difuran-2-carbohydrazides 5a, b were reacted with aryl or alkyl isothiocyanates to give the corresponding thiosemicarbazides 6a–h. Cyclization of the substituted thiosemicarbazides with sodium hydroxide led to the formation of benzo[1,2-b:5,4-b′]difuranyl-1,3,4-triazoles 7a–f. Desulfurization of thiosemicarbazides by mercuric oxide gave benzo[1,2-b:5,4-b′]difuranyl-1,3,4-oxadiazoles 8a–f. Treatment of thiosemicarbazides with ethyl bromoacetate or α-bromopropionic acid yielded benzo[1,2-b:5,4-b′]difuranyl-carbonyl-hydrazono-4-thiazolidinones 9a–f and 10a–f, respectively. Furthermore, the reaction of the thiosemicarbazides with phosphorus oxychloride gave benzo[1,2-b:5,4-b′]difuranyl-1,3,4-thiadiazoles 11a–f. Some compounds in this study were biologically evaluated for their ability to bind to DNA. 相似文献
20.
I. V. Zubets Yu. A. Boikov I. V. Viktorovskii K. A. V'yunov 《Chemistry of Heterocyclic Compounds》1986,22(10):1148-1152
The cyclization of aldehyde thiosemicarbazones with ferric chloride yielded 2-amino-5-aryl-1,3,4-thiadiazoles, forming 2-chloro-5-aryl-1,3,4-thiadiazoles in the Sandmeyer reaction. The mass-spectrometric behavior of the 2-amino- and 2-chloro-5-aryl-1,3,4-thiadiazoles was studied; the typical routes of fragmentation characteristic of each group of compounds were found.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1416–1419, October, 1986. 相似文献