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1.
Diflunisal and Felbinac, two FDA-approved NSAIDs and other biphenyl carboxylic acids were prepared in one step by a simple and clean Suzuki cross-coupling reaction using an easily synthesized, air and moisture stable, palladium-diamine complex. The yield (93%) for the one-step preparation of Diflunisal is the best reported without using a glovebox and a phoshine-based catalyst.   相似文献   

2.
This article describes the simple hydrodehalogenation of halogenated anilines and their derivatives by the action of Raney aluminium-nickel alloy in aqueous alkaline solution at room temperature. The reaction course was monitored by means of 1H nuclear magnetic resonance (NMR) spectroscopy and GC-MS spectra.   相似文献   

3.
Ionic liquids (IL) are gaining importance as green solvents. Imidazolium ionic liquid [bmim]+[Cl], an environmentally benign solvent, was found to promote the Diels-Alder reaction between anthrone and maleimides at room temperature with excellent yields. The ionic liquid played a dual role as solvent and catalyst.   相似文献   

4.
The reaction mechanism between AlX and HX (X = Br, Cl, and F) have been characterized in detail using DFT as well as the ab initio method. The reaction yielding AlX3 and molecular hydrogen was calculated to be highly exothermic. The present calculations also show that the possible routes to the trihalides species start more favorable with the primary insertion product AlX2H than with the biadduct AlX(HX)2 one.   相似文献   

5.
A novel hydroxyamino phosphane was synthesised through the reaction of 2-imidazolidinone with ClPPh2 and subsequently reaction of the resulting bisphosphino derivative with the Grignard reagent BrMgC5H11. The interaction of the pentyl substituent with one of the two phosphino groups and the structure in solution is shown by multinuclear NMR-spectroscopy..   相似文献   

6.
Sulphonimide based organocatalyst was used to catalyze the aldol reaction in ionic liquid media. On the basis of yield and selectivity the ionic liquid mediated system was found superior in comparison with organic solvents. The added advantages of this ionic liquid mediated organocatalysis are easy recovery of product and the recyclability of the organocatalyst.   相似文献   

7.
A rapid and an efficient one-pot method for the synthesis of quinoxalines catalysed by ZnO-beta zeolite at room temperature is described. This environmentally benign method provides several advantages over methods that are currently employed such as a simple work-up, mild reaction conditions, good to excellent yields, and a process to recover and reuse the catalyst for several cycles with consistent activity.   相似文献   

8.
Natural scolecite has been found as an effective catalyst for the one-pot synthesis of 2,4,5-triarylimidazole derivatives via a three component reaction using benzil or benzoin, aldehydes and ammonium acetate. This method provides several advantages such as being environmentally benign, reusable, possessing high yields with increased variations of the substituents in the product and preparative simplicity.   相似文献   

9.
During the diazo-coupling reaction, nucleophilic displacement of a nitro group was also observed. This was the main reaction (1→7) when the starting amine bore either a chlorine or methoxy group at the para position (1b–c). The newly prepared compounds (7) might serve as convenient building blocks in synthesis of some heterocycles.   相似文献   

10.
Phase equilibria established in the PbO - BiVO4 system over the whole component concentration range up to 1000°C have been investigated. A phase diagram has been constructed using DTA and XRD.   相似文献   

11.
The Ugi reaction with formylphenylboronic acid derivatives as the carbonyl component proceeds to give the corresponding boron-containing dipeptide derivatives (Ugi products) in good yields.   相似文献   

12.
Xenbucin 1, an analgesic drug, was synthesized in 4 steps using two different routes. The biaryl fragment could successfully be produced via a Pd/C catalysed Suzuki coupling in water using sodium tetraphenylborate as a phenylation reagent. Overall yields of the routes were 36% and 59%, respectively.   相似文献   

13.
The oxidation processes of 2,6-diisopropylnaphthalene and 4,4′-diisopropylbiphenyl with oxygen in the presence of a catalyst, composed of copper(II) chloride and tetrabutylammonium bromide, were investigated. It was found that, in essence, only one isopropyl group undergoes oxidation, and obtained mixtures contained mainly peroxide, alcohol, ketone and only small amounts of hydroperoxide.   相似文献   

14.
1-benzyl-3-methyl imidazolium hydrogen sulphate [bnmim][HSO4] was found to be an effective catalyst for the condensation reaction of indoles and derivatives with benzaldehydes in microwave irradiation with lower reaction time and higher yields to give bis(indolyl) methanes.   相似文献   

15.
The catalytic effect of VSi2 on initial stages of the liquid-phase oxidation of cyclooctene by molecular oxygen was studied. The vanadium disilicide influences on the oxidation process in the presence of hydroperoxide. VSi2 takes part in a radical formation stage by catalysis of hydroperoxide decomposition reaction. The catalyst was investigated before and after reaction using FTIR spectroscopy. From the data obtained, the kinetic model of the catalytic oxidation process was proposed and the equation for the reaction rate was derived. The equation has described all observed dependences of reaction rate on the concentration of reactants and content of catalyst.   相似文献   

16.
The palladium(0) catalyzed amination of allylic acetates and carbonates derivatives from terpenic olefins was carried out under mild conditions. The reaction offers a very good method for the preparation of allylic amines and thus to provide a useful entry to new functionalized terpenic olefin products. The mechanism involving a formation of p-allyl-palladium intermediate complex is in good agreement with the results obtained with the optically active substrates, as well as via an analysis of the observed regio-and stereoselectivity.   相似文献   

17.
18.
The kinetics of the C-S coupling of arylmagnesium bromides with phenyl tosylate has been studied in THF: toluene at 90°C. The reaction is first order in Grignard reagent and first order in phenyl tosylate. Kinetic data, Hammett relationship and activation parameters are consistent with a nucleophilic addition mechanism involving rate determining attack of carbanion to sulfonyl group followed by a fast phenoxide group leaving.   相似文献   

19.
A one-pot multi-component reaction is developed for the efficient synthesis of 4,5-dibenzylidene octahydroacridines in high yields. The reaction is performed by the tandem reaction of three molar equivalent aromatic aldehydes with two molar equivalent 4-alkylcyclohexanone in the system of NH4OAc/HOAc under microwave irradiation.   相似文献   

20.
The 1H-NMR and quantum chemical analysis of the stability of tautomers of cinnamoyl pyrone derivatives and vinylogs has been studied. The relationship between the structure of the most stable tautomer and its spectral properties has been investigated. It has been determined that the tautomer of highest stability (88–100 molar %) has an α-pyrone structure and exhibits a trans-conformation in the cinnamoyl fragment. An intense fluorescence of dyes has been observed in non-polar solvents with cinnamoyl fragments having electron-donating substituents or several double bonds in the polymethine chain. A gradient in solvent polarity resulted in fluorescence quenching which permits the use of the dyes as intensometric fluorometric probes for medium polarity examination.   相似文献   

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