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1.
《Mendeleev Communications》2023,33(1):11-13
Carbonyl-containing furan-3-carboxylates were obtained by the refluxing of alkyl 3-bromo-3-nitroacrylates and acyclic CH-acids, namely, pentane-2,4-dione and alkyl 3-oxo-butanoates in methanol in the presence of equimolar amounts of potassium acetate. The products can be prepared by the similar processing of 2-nitro-2,3-dihydrofuran-3-carboxy-lates being the intermediates in the total transformation. 相似文献
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Carlos Corral Mahmoud B. El-Ashmawy Jaime Lissavetzky Ignacio Manzanares 《Journal of heterocyclic chemistry》1987,24(5):1301-1303
The indirect introduction of an azolyl group in position 5 of compound 1 by an easy two-step procedure taking place at room temperature is described. A similar procedure yields the 4-chloro derivatives of these 5-azolyl compounds. The same method is applied for the introduction of a 5-azido group and from the 5-azido compounds, 5-v-triazolyl derivatives are obtained by a known method. 相似文献
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Robert E. Leard John H. Bedenbaugh Angela O. Bedenbaugh 《Journal of heterocyclic chemistry》1983,20(5):1363-1366
The 5-bromo, 5-iodo, and 5-nitro derivatives of 6-methyl-3-nitroso-2,4-pyridinediol were synthesized and shown to produce colored complexes with a number of Group VIII metal ions. Also synthesized were the 1-pentyl and 1-octyl esters of 4,6-dihydroxy-5-nitrosopyridine-3-carboxylic acid. These compounds showed potential as solvent extraction reagents for certain Group VIII metals. 相似文献
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S. F. Vasilevskii A. N. Sinyakov M. S. Shvartsberg I. L. Kotlyarevskii 《Russian Chemical Bulletin》1976,25(10):2134-2138
1. | Depending on the conditions, the reaction of methyl aryl ketones with phosphorus pentachloride leads to products from substitution of the carbonyl oxygen by chlorine, αβ-dichlorovinylarenes, or compounds with higher degrees of chlorination. |
2. | By eliminating a molecule of hydrogen chloride under the influence of an equimolar amount of sodium amide in ammonia, substituted, α,β-dichloroethylenes give high yields of the respective 2-chloroacetylene. |
3. | The synthesis of a series of ethynyl- and β-chloroethynylpyrazoles from methylpyrazolyl ketones was realized. |
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A general three- or four-step synthesis of cis- and trans-substituted cucurbitine (3-aminopyrrolidine-3-carboxylic acid) derivatives from methyl 2-nitroacetate is reported. The first step utilizes a Knoevenagel condensation with five different aromatic imines or their corresponding aldehydes to form (Z/E)-mixtures of α-nitro acrylates. The second step gives rise to the pyrrolidine-core structures of the title compounds by a 1,3-dipolar cycloaddition reaction using an azomethine ylide. The last step consists of reduction of the nitro group to yield both diastereoisomers of the corresponding 4-aryl cucurbitine methyl esters. 相似文献
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Alison A. Edwards Gangadharar J. Sanjayan Raquel Soengas George E. Tranter 《Tetrahedron》2006,62(17):4110-4119
Templated tetrahydrofuran-based γ-azido esters were prepared with the C-2 and C-4 functionalities in cis and trans relative configurations. This was achieved by ring contraction of the suitably protected 2-O-triflates of pentono-1,5-lactones (d-ribose and l-arabinose) with subsequent introduction of the azide via the 4-O-triflate. Access to a corresponding β-azido ester was achieved in good yield. Little elimination product was observed by introduction of the azide via the 3-O-triflate. These azido esters are scaffolds, which may be predisposed to adopt secondary structural motifs, for example, for use as peptidomimetics; they may also be utilised for the preparation of stereodiverse compound libraries. 相似文献
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V. V. Shchepin A. E. Korzun N. V. Bronnikova 《Russian Journal of Organic Chemistry》2004,40(7):998-1002
Zinc enolates derived from 1-aryl-2-bromoalkanones react with alkyl 5,5-dimethyl-2-oxo-2,5-dihydrofuran-3-carboxylates to give alkyl 4-(1-alkyl-2-aryl-2-oxoethyl)-5,5-dimethyl-2-oxotetrahydrofuran-3-carboxylates. Reactions of the latter with amines, such as p-toluidine, cyclohexylamine, and piperidine, lead to the corresponding carboxamides. 相似文献
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V. A. Gorpinchenko D. V. Petrov L. V. Spirikhin V. A. Dokichev Yu. V. Tomilov 《Russian Journal of Organic Chemistry》2006,42(11):1706-1710
Reactions of methyl exo-3,4-diazatricyclo[5.2.1.02.6]dec-4-ene-5-carboxylate with methyl diazoacetate, methyl iodide, ethylene oxide, acetic acid, nitrosonium cation, and sulfur led to the formation of a series of N3-substituted exo-3,4-diazatricyclo[5.2.1.02,6]dec-4-enes. 相似文献
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A procedure has been developed for the synthesis of methyl 6-alkyl-3-cyano-2-halopyridine-4-carboxylate by three-component reaction of 4-oxoalkane-1,1,2,2-tetracarbonitriles with hydrogen halides in methanol. 相似文献
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V. V. Shchepin A. E. Korzun Yu. Kh. Sazhneva 《Russian Journal of Organic Chemistry》2004,40(10):1500-1502
Zinc enolates derived from ethyl 4-bromo-2,2,4-trimethyl-3-oxopentanoate and 4-bromo-4- ethyl-2,2-dimethyl-3-oxohexanoate react with 2-furan-, 2-thiophene-, 1-(3-nitrophenyl)-2-pyrrole-, 1-acyl-3-indole-, and 2-pyridinecarbaldehydes to give the corresponding 6-hetaryl-5,5-dialkyl-3,3-dimethyltetrahydropyran-2,4-diones.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 10, 2004, pp. 1549–1551.Original Russian Text Copyright © 2004 by Shchepin, Korzun, Sazhneva. 相似文献
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M. I. Komendantov R. R. Bekmukhametov R. R. Kostikov 《Chemistry of Heterocyclic Compounds》1978,14(8):843-846
The thermal isomerization of 5-methoxy-3-arylisoxazoles to methyl 3-aryl-2H-azirine-2-carboxylates was subjected to a kinetic study. A correlation between the isomerization rate constants and the
+ constants of the substituents in the aromatic ring is observed. The enthalpies of formation of a number of isoxazoles and 2H-azirines were calculated. The effect of the nature of the substituents on the mutual isomerization of isoxazoles and azirines is discussed. The results make it possible to refute the approved and previously proposed diradical mechanism for the isomeric transformations and are in agreement with a nitrene mechanism for the formation of azirines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1053–1056, August, 1978. 相似文献
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Condensation of methyl 4-oxobutanoate with nitroethane in the presence of 4-dimethylaminopyridine, followed by treatment with acetic anhydride, afforded a nitroacetoxyester 10b . Subsequent reaction with isocyanoacetate esters and DBU in refluxing tetrahydrofuran gave the synthetically valuable pyrroles 1a and 1b. 相似文献
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Sandra Rae Etson Ronald J. Mattson J. Walter Sowell 《Journal of heterocyclic chemistry》1979,16(5):929-933
A facile route for the synthesis of substituted pyrrolo[2,3-d]pyrimidine-2,4-diones from substituted 2-amino-3-cyano-4-methylpyrroles is reported. 相似文献
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Matthias Moens Matthias De SchrijverPeter ten Holte Jan-Willem ThuringFrederik Deroose Norbert De Kimpe 《Tetrahedron》2012,68(45):9284-9288
A strategy toward the synthesis of functionalized 5,5-difluoropiperidines, a class of compounds with potential as building block in medicinal chemistry, was developed. In a three-step procedure 2,2-difluoroglutaric anhydride was synthesized starting from ethyl bromodifluoroacetate. This key intermediate reacts fluently with various imines to yield 5,5-difluoropiperidinone carboxylic acids. Subsequent esterification of the obtained carboxylic acids enabled the isolation of trans-substituted 5,5-difluoro-2-arylpiperidinone-3-carboxylates as the major isomers. Reduction of the difluorinated piperidinonecarboxylates using borane gave rise to new trans-2-aryl-1-benzyl-5,5-difluoro-3-hydroxymethylpiperidines in excellent yields. 相似文献