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Anjaiah Aitha Satyanarayana Yennam Manoranjan Behera Jaya Shree Anireddy 《Tetrahedron letters》2017,58(6):578-581
The reaction of 1,3,4-oxathiazol-2-one derivative with 2-arylidene-1,3-indandione to furnish novel spiroindene-1,3-dione isothiazoline derivatives by Michael/1,3-dipolar [3+2]-cycloaddition reaction was investigated. The key 1,3-dipolar cycloaddition reaction step was examined in toluene solvent at reflux temperature to obtain mixture of two regioisomers (6a and 6b – 14a and 14b) and single isomers (15–20). The scope of this new reaction was demonstrated with many examples with high reactivity and yields. 相似文献
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Marcel Morvan Guy Nadler Richard G. Zimmermann 《Journal of heterocyclic chemistry》1991,28(5):1365-1368
The synthesis of the new heterocycle 1,3,4-selenadiazin-2-one is described, based on the preparation of the analogue heterocycle 1,3,4-thiadiazin-2-one. The related cyclization between an α-haloketone and a thiocarbazate cannot readily be employed within the selenium series. Therefore a new route was developed based upon a diazotization/hydrolysis sequence of the related 2-amino-1,3,4-selenadiazine. 相似文献
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5-Methyl-2-phenyl-1,3,4-oxadiazin-6-one undergoes cycloaddition with 2-methylpropenylpyrrolidine. One of the cycloadducts is derived from the Diels-Alder reaction of a transient azaketene tautomer. 相似文献
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In the presence of Pd(II) catalyst and copper(II) bromide, 2-(arylmethylene)cyclopropylcarbinols undergo ring enlargement to deliver (arylcyclobutenyl)carbinols or hydrogenated furans in good yields under mild conditions; mechanisms accounting for the distinct products have been proposed on the basis of control and deuterium labeling experiments. 相似文献
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Force-field calculations in combination with 1H NMR spectroscopy, IR data and X-rays diffraction unambiguously delineate the conformational properties of tetrahydropyran-2-one derivatives which exhibit psychostimulant and antidepressive activity. 相似文献
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Yu. M. Volovenko V. A. Litenko T. V. Khrapak F. S. Babichev 《Chemistry of Heterocyclic Compounds》1983,19(11):1167-1169
The reaction of arylacetonitriles with the methyl ester of 3-hydroxybenzo[b]thiophene-2-carboxylic acid in the presence of a basic catalyst leads to the previously unreported 2-amino-3-arylbenzo[4,5]thieno[3,2-b]pyran-4-ones. Under the same conditions, the ethyl ester of 4,6-dimethyl-3-hydroxythieno[3,2-c]pyridine-2-carboxylic acid reacts to form derivatives of a new heterocyclic system, pyrano[2,3-4,5]-thieno[3,2-c]pyridine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1476–1478, November, 1983. 相似文献
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Acylation of 5-amino-3H-1,3,4-thiadiazolin-2-one (2) was undertaken selectively at either the 3-NH position or at 5-amino group depending on reaction conditions. The 3-NH is highly acidic and acylation takes place with acid anhydrides at this position in high yields in the presence of pyridine or triethylamine. The diacylation of both the 3-position and the 5-amino group was only possible via the 5-amino-3-acyl-1,3,4-thiadiazolin-2-one intermediates 4 . Under neutral conditions, acylation only occurs at the 5-amino group with acyl chlorides forming 5-acylamino-3H-1,3,4-thiadiazolin-2-ones 5 . 5-Acetylamino-3H-1,3,4-thiadiazolin-2-one can also be synthesized by the thermal transformation of 5-amino-3-acetyl-1,3,4-thiadi-azolin-2-one in acetic acid. 相似文献
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M. M. Hamad S. A. Said Y. M. El-Ekyabi 《Monatshefte für Chemie / Chemical Monthly》1996,127(5):549-555
Summary The title compound (4) was synthesized from thioglycolic acid hydrazide and ethyl chloroformate. The reactions of4 with aromatic amines, amino derivatives, hydrazine hydrate, hydroxylamine, and formamide were studied. Addition of compound4 to ,-unsaturated compounds,i.e. chalcones, maleic anhydride, quinones, and acrylonitrile, was investigated.
Synthese und Reaktionen von 2-Mercaptomethyl-1,3,4-oxadiazolin-5-on
Zusammenfassung Die Titelverbindung (4) wurde aus Thioglycolsäurehydrazid und Chlorameisensäureethylester hergestellt. Die Reaktionen von4 mit aromatischen Aminen, Aminoderivaten, Hydrazinhydrat, Hydroxylamin und Formamid sowie die Addition von4 an ,-ungesättigte Verbindungen (Chalkone, Maleinsäureanhydrid, Chinone, Acetonitril) wurden untersucht.相似文献
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The ring-opening abilities of amines toward 1,3,4-oxadiazolines, 2-phenyl-1,3,4-oxadiazolin-5-one ( 1a ) and 2-phenyl-1,3,4-oxadiazoline-5-thione ( 1b ), were investigated with relation to their basicities or pKb values. Oxadiazolines 1a and 1b were easily reacted with amines such as benzylamine and aniline, but not with p-nitroaniline, to form the corresponding ring-opening adducts. The reactions of both 1a and 1b with o-phenylenediamine produced benzodiazoles with the liberation of benzoylhydrazide, whereas the reactions with o-aminobenzamide furnished quinazolines with the liberation of ammonia. o-Aminophenol and o-aminothiophenol were also reacted with 1a and 1b both of them giving 1,5-dibenzoylcarbohydrazide from 1a and 1,2-dibenzoylhydrazine from 1b. From the conditions affording the corresponding ring-opening adducts or reaction products, the ring-opening abilities of the amines toward 1a and 1b are in good correlation with the strength of their basicities or pKb values. The ring-opening of oxadiazolines were proved to occur with anilines. Therefore, the other reactions are also supposed to proceed via the ring-opening steps. 相似文献
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N. M. Przheval'skii L. Yu. Kostromina I. I. Grandberg 《Chemistry of Heterocyclic Compounds》1988,24(2):154-158
The kinetics of the Fischer thermal indolization of monosubstituted cyclohexanone arylhydrazones was studied by the spectrophotometric method. The enthalpy and entropy of activation of the reaction were calculated. The data obtained were interpreted in terms of a consistent mechanism of formation of a carbon-carbon bond (the [3,3]-sigmatropic shift). It was found that the influence of the electronic factors on the rate of the sigmatropic rearrangement is inappreciable.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 188–192, February, 1988. 相似文献
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Conclusions The direction of the reaction of potassium dialkyldithiophosphate with thioepoxide compounds is determined by the nature of the substituent in the-position to the thioepoxide ring.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1910–1912, August, 1970. 相似文献
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N. I. Korotkikh O. P. Shvaika L. A. Gorbunov 《Chemistry of Heterocyclic Compounds》1999,35(3):358-362
Epoxide derivatives of 2,5-bis-oxyphenul-1,3,4-oxadiazoles and fluorescein, which are luminescent epoxide monomers, are synthesized. Their luminescence properties are studied.L. M. Litvinenko Institute of Physical Organic Chemistry, National Academy of Sciences of Ukraine, Donetsk 340114Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 407–412, March, 1999. 相似文献
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《Liquid crystals》1998,24(5):787-791
Four series of di(4-alkoxycarbonylphenyl) terephthalates with different lateral substituents in the central ring and lengths of the terminal alkyl groups were synthesized. The influence of the lateral substituent on thermodynamical parameters of the phase transitions and elastic properties of the nematic phases (ratio of bend elastic constant to diamagnetic anisotropy K3/Delta chi) were studied by polarizing optical microscopy, differential scanning calorimetry and observations of the Freedericksz transition. It was found that increasing the alkyl chain length and the substituent size in the sequence H, Cl, Br, NO2 results in reduction in stability of the crystal and (as frequently observed in other cases) the liquid crystal phases. The changes in the bend elastic constant and the melting enthalpy caused by the substituent variation are correlated with each other, a fact that is explained by the dependence of short-range lamellar packing on size and polarity of substituent. 相似文献
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Thermal extrusion of sulfur dioxide from 1-methyl-3-(5-chlorosulfonyl-1,3,4-thiadiazol-2-yl)urea ( 1 ) provides 1-methyl-3(5-chloro-1,3,4-thiadiazol-2-yl)urea in quantitative yield. 相似文献