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1.
An investigation has been conducted into the effect of the acid and dehydrogenating functions of an aluminoplatinum catalyst on the synthesis of 2-methylimidazole from ethylenediamine and acetic acid. It has been established that formation of the intermediate 2-methylimidazoline involves the acid Al2O3 centers and its rate of formation is greater than the rate of its subsequent dehydrogenation to 2-methylimidazole on the Pt centers. The symbatic nature of the variations in the 2-methylimidazole yield and the surface area of the platinum in the aluminoplatinum catalyst has been demonstrated.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 9, pp. 1992–1996, September, 1992.  相似文献   

2.
The synthesis of C-alkylimidazoles from 1,2-diamines and carboxylic acids over bifunctional platinum—alumina catalysts has been studied. It has been shown that this method is effective for the synthesis of 2-alkyl and 2,4-dialkylimidazoles including imidazoles with long-chain alkyls. The effect of the reaction temperature, space velocity of the flow of the raw materials, and dilution by hydrogen on the yield of product has been examined for the example of the synthesis of 2-methylimidazole from ethylenediamine and acetic acid, and the stability of the catalyst in continuous reaction cycles with intermediate oxidative regeneration has been studied. The composition of the accompanying products has been established and a mechanism proposed for their formation.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 117913. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 4, pp. 932–940, April, 1992.  相似文献   

3.
本文优化了溴乙烷与2-甲基咪唑的N-烷基化反应条件,并且高收率地合成了一系列具有抗菌活性的1-烷基-2-甲基咪唑衍生物。  相似文献   

4.
An investigation has been conducted into the staged synthesis of 2-methylimidazole from ethylenediamine and acetic acid in the presence of a bifunctional aluminoplatinum catalyst. It has been shown that the formation stage of 2-methylimidazoline occurs more quickly on -Al2O3 than its dehydrogenation on the Pt centers. From a comparison of the processes of dehydrogenation of 2-methylimidazoline in the molten phase and in aqueous solution it follows that the water eliminated in the imidazoline formation stage could cause the decrease in activity during the dehydrogenation on the Pt centers. The structures of the secondary and intermediate products have been established for each stage of the process and their formation routes are discussed.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 9, pp. 1997–2002, September, 1992.  相似文献   

5.
A highly efficient copper-catalyzed approach to form amide bonds from formamides and carboxylic acids was developed.This protocol shows broad substrate scopes and high yields in the presence of 1 mol% catalyst and 4.0 equiv.formamides.  相似文献   

6.
A simple and efficient copper-catalyzed method for the synthesis of aromatic carboxylic acids in moderate to high yields with great functional-group compatibility in the substrates has been developed. The new method uses readily available arylboronic acids and acetyl acetate as the starting materials and inexpensive CuI as the catalyst.  相似文献   

7.
The oxidation of terminal alkenes was smoothly catalyzed by a recyclable and environmentally friendly catalytic system: [(C18H37)2N(CH3)2]3[PW4O16]/H2O2/formic acid. This new catalytic system is not only capable of catalyzing oxidation of terminal alkenes with a phase-transfer character, but also under solvent-free conditions, avoiding the use of chlorinated solvents. Many different kinds of terminal alkenes could be converted to the corresponding 1,2-diols of high purity in high yields. The catalyst could be easily separated and reused after reaction. Both fresh and used [(C18H37)2N(CH3)2]3[PW4O16] catalyst was characterized by Raman and FTIR.  相似文献   

8.
《Tetrahedron》2019,75(34):130467
Effective synthesis of novel sulfamates from various carboxylic acids has been developed in the presence of chlorosulfonyl isocyanate (CSI) in mild conditions. Several acids, bases and solvents effects were investigated for one-pot synthesis sulfamates as a catalyst. Finally, triflic acid was found to possess efficiently under optimized conditions in acetonitrile. This method is easy, fair price and practical. It can be synthesized on grams and milligrams scale.  相似文献   

9.
Summary The tetrabutylammonium bromide catalyzed esterification of salts of carboxylic acids1 a–e with 2-propenyl halides2 a,b is described.
Phasentransferkatalysierte Synthese von 2-Propenylestern von Carbonsäuren (Kurze Mitt.)
Zusammenfassung Es wird die tetrabutylammoniumkatalysierte Veresterung von Carbonsäuresalzen1 a–e mit 2-propenylhalogeniden2 a,b beschrieben
  相似文献   

10.
A simple, mild and high yielding method for the conversion of various carboxylic acids to nitriles has been developed using diphosphorus tetraiodide in combination with ammonium carbonate at room temperature.  相似文献   

11.
Herein we report triphenyl borate as a new catalyst for synthesis of amides by catalytic condensation of carboxylic acids and amines. Our protocol is applicable for synthesis of wide range of amides furnishing excellent yields up to 92%. In addition developed method requires low catalyst loading, short time, less amount of solvent, works under air atmosphere and notably no need of azeotropic reflux using special Dean Stark apparatus or molecular sieves.  相似文献   

12.
Petersen TB  Khan R  Olofsson B 《Organic letters》2011,13(13):3462-3465
An efficient arylation of carboxylic acids with diaryliodonium salts has been developed, giving aryl esters in high yields within short reaction times for both aromatic and aliphatic substrates. The transition-metal-free conditions are compatible with a range of functional groups, and good chemoselectivity is observed with unsymmetric diaryliodonium salts. Furthermore, steric hindrance in the ortho positions is well tolerated both in the carboxylic acid and in the diaryliodonium salt, yielding aryl esters that cannot be obtained via other esterification protocols.  相似文献   

13.
荣国斌 《有机化学》1996,16(1):68-71
N, N-二甲基取代酰胺可以方便地由脂肪族或芳香羧酸与四(二甲氨基)硅烷在无水溶剂中反应制得。  相似文献   

14.
A variety of beta- or alpha-C-glycosides may be readily accessed in an entirely stereoselective fashion from esters derived from the reaction of carboxylic acids and 3-hydroxy glycals, by way of a tandem reaction sequence of Tebbe methylenation and Claisen rearrangement. Though of wide scope, for example allowing the synthesis of 1-6 linked C-disaccharides, the methodology does not currently allow the synthesis of C-glycosyl alpha-amino acids.  相似文献   

15.
A mild method for the synthesis of 2-ketopyrroles from carboxylic acids via 2-pyridylthiolesters and pyrrylmagnesium chloride is described.  相似文献   

16.
Microwave-assisted synthesis of 2-oxazolines from carboxylic acids using the open vessel technique is described. This efficient method involves direct condensation of carboxylic acids with excess 2-amino-2-methyl-1-propanol at 170 °C to give the corresponding 2-oxazolines in moderate to excellent yields.  相似文献   

17.
黄炳南  吴范宏 《有机化学》1993,13(4):403-404
本文报道了一种新的合成多氟羧酸的方法:即在银(I)离子存在下,甲酸钠与多氟烷基碘代烷反应的结果。  相似文献   

18.
Aggregation of saturated mesocyclic diamine 1,4-diazacycloheptane (dach) or piperazine (pipz) and diversiform carboxylic acids with mono- or di-carboxyls yields a series of novel binary supramolecular adducts via two-point molecular recognition. All the supramolecular assemblies were obtained by solvent evaporation method from different media. X-ray single-crystal diffraction analyses reveal that these supramolecular moieties present 1D chain motif, 2D flat, corrugated sheet structures and 3D CdSO4, pillar-layered networks through carboxylate-amide N–H⋯O, as well as its proton transfer form N+–H⋯O, carboxyl head to tail O–H⋯O, and extended hydrogen-bonding interactions. Their compositions and structures were also confirmed by Fourier transform infrared (FT-IR) spectroscopy. Thermal stability of these binary crystalline adducts has been investigated by thermogravimetric analysis (TGA), suggesting similar thermal stabilities.  相似文献   

19.
An efficient method involving pyridine activation of the carboxylate-phosphate anhydride pathway is described resulting in a direct synthesis of esters from carboxylic acids and alcohols, as well as in the formation of useful amide and peptide derivatives. The reaction proceeds with retention of configuration with both chiral secondary alcohols and α-amino acid derivatives. Ester and amide products can be isolated directly in high yield due to the water soluble nature of the side products.  相似文献   

20.
A facile method for the activation of hydroxy-substituted carboxylic acids using benzotriazole chemistry without prior protection of the hydroxy substituents is presented. The N-acylbenzotriazole intermediates 2a-g, 6a-d, and 9a-c have been used for high-yielding synthesis of both aliphatic (3a-l) and aromatic (7a-h, 10a-f) hydroxy carboxamides. High yields of aromatic hydroxy esters 12a-h and 13a-i were obtained using either neat alcohols in neutral microwave conditions or nucleophilic alkoxides and the intermediate N-(arylacyl)benzotriazoles. Moderate yields were obtained in the case of aliphatic hydroxy esters 11a,b and thiolesters 11e-g from the intermediates 2a-c.  相似文献   

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