In this letter,a mild and efficient procedure for synthesis of phenacyl derivatives under homogenous catalysis in the presence of tetrabutylammonium bromide in aqueous media is described.The nucleophilic substitution ...In this letter,a mild and efficient procedure for synthesis of phenacyl derivatives under homogenous catalysis in the presence of tetrabutylammonium bromide in aqueous media is described.The nucleophilic substitution reactions were performed under ecofriendly conditions and gave the corresponding products in high yields and short reaction times.展开更多
The effects of 4-(2-hydroxyphenyl)-2-(morpholin-4-yl)-1,3-thiazole(Pr02), 1-(3,5-dibromo-2-hydroxyphenyl)-1-oxoethan-2-yl-N,N-diethyldithiocarbamate(Pr04) and 1-(5-bromo-2-hydroxy-3-methylphenyl)-1-oxoethan-2-yl-Oethy...The effects of 4-(2-hydroxyphenyl)-2-(morpholin-4-yl)-1,3-thiazole(Pr02), 1-(3,5-dibromo-2-hydroxyphenyl)-1-oxoethan-2-yl-N,N-diethyldithiocarbamate(Pr04) and 1-(5-bromo-2-hydroxy-3-methylphenyl)-1-oxoethan-2-yl-Oethyl xanthate(Pr06) on the aqueous oxidation of chalcopyrite(CuFeS2) in air-equilibrated solution at a temperature of 25 ℃ and a pH of 2.5 were studied. The effects were investigated by using potentiodynamic polarization, electrochemical impedance spectroscopy(EIS), scanning electron microscopy coupled with energy dispersive X-ray(SEM/EDX) analysis, aqueous batch experiments, Fourier transform infrared(FTIR) spectroscopy, Raman scattering and quantum chemical calculations. It is found that the anodic current densities decrease in the order of EtOH > Pr02 > Pr04 > Pr06. These results, along with those of the EIS measurements, show that Pr02, Pr04 and Pr06 are effective anodic inhibitors of chalcopyrite aqueous oxidation. Both Raman scattering and FTIR spectroscopy indicate that the elemental sulfur, polysulfide and ferric oxyhydroxides that form on the surface of the mineral are not responsible when it comes to the aqueous oxidation inhibition of chalcopyrite. Quantum chemical calculations show that the adsorption of the tested compounds on the chalcopyrite surface is energetically favorable and so, it can explain the inhibiting effects that were observed.展开更多
An efficient method is reported for the synthesis of phenacyl esters by reaction of carboxylic acids withα-bromoacetophenone promoted by potassium fluoride in ionic liquid [Bmim]PF6, the yield of the reaction is almo...An efficient method is reported for the synthesis of phenacyl esters by reaction of carboxylic acids withα-bromoacetophenone promoted by potassium fluoride in ionic liquid [Bmim]PF6, the yield of the reaction is almost quantitative and the products are essentially pure.展开更多
The Darzens condensation reaction of aromatic aldehydes with phenacyl chloride proceeded very efficiently in a water suspension medium in the presence of triethylbenzylammonium chloride and only trans 2,3 epoxy ...The Darzens condensation reaction of aromatic aldehydes with phenacyl chloride proceeded very efficiently in a water suspension medium in the presence of triethylbenzylammonium chloride and only trans 2,3 epoxy 1,3 diaryl 1 propanones were formed which can be isolated simply by filtration. The structures of these compounds were confirmed by elemental analysis, IR and 1H NMR spectra. Their configurations are in agreement with that of the same compounds reported in the literature. Compared to the classical Darzens condensation, this new method has the advantages of good yields, high stereoselectivity, low running cost inexpensive and environmentally benign procedure.展开更多
The kinetics of SN2 reaction between phenacyl bromide and various amines in 12 different solvents were studied. Solvent effects on the rate of this reaction and free energy of activation, ΔG#, were interpreted by app...The kinetics of SN2 reaction between phenacyl bromide and various amines in 12 different solvents were studied. Solvent effects on the rate of this reaction and free energy of activation, ΔG#, were interpreted by applying the Abraham-Kamlet-Taft (AKT) equation. The solvent polarity (π1*), solvent hydrogen-bond basicity (β1) and Hildebrand cohesive density energy (δ2H) are those parameters which increase the rate constant and decrease ΔG#, while solvent hydrogen-bond acidity (α1) will have the compensatory effect. A comparison among obtained values of second rate constants, k2 for different amines in a given solvent indicates that the amine reactivities are highly dependent on their structures. The consequent decrease of the rate constant for different amines in any given solvent was found to be: primary > secondary > tertiary. This order results from steric effects of amines.展开更多
A simple and efficient synthesis of highly substituted pyrroles was achieved in water medium via multi-component strategy, using amine, DMAD/DEAD as well as phenacyl bromide catalyzed by β-CD. Utilizing this protocol...A simple and efficient synthesis of highly substituted pyrroles was achieved in water medium via multi-component strategy, using amine, DMAD/DEAD as well as phenacyl bromide catalyzed by β-CD. Utilizing this protocol various pyrrole derivatives were synthesized in good to excellent yields.展开更多
An one pot method is used for the synthesis of 1,2,4,6 tetraaryl 1,4 dihydropyrazine by the reaction of phenacyl bromides with arylamines.This synthetic method provides an easier and simpler access to this kind of com...An one pot method is used for the synthesis of 1,2,4,6 tetraaryl 1,4 dihydropyrazine by the reaction of phenacyl bromides with arylamines.This synthetic method provides an easier and simpler access to this kind of compounds as compared with the that in reference.展开更多
The synthesis of C-substituted and N-substituted pyrrole is described by the reaction of phenacyl bromides, pentane-2, 4-dione and amine in aqueous medium using DABCO as a catalyst. The method is very convenient and a...The synthesis of C-substituted and N-substituted pyrrole is described by the reaction of phenacyl bromides, pentane-2, 4-dione and amine in aqueous medium using DABCO as a catalyst. The method is very convenient and applicable for alkyl as well as aryl amines and phenacyl bromides. The procedure is amenable for the synthesis of new substituted pyrroles. Moreover, aqueous medium makes the method more eco-friendly.展开更多
基金Partial support for this work by Islamic Azad University,Mahshahr branch research council
文摘In this letter,a mild and efficient procedure for synthesis of phenacyl derivatives under homogenous catalysis in the presence of tetrabutylammonium bromide in aqueous media is described.The nucleophilic substitution reactions were performed under ecofriendly conditions and gave the corresponding products in high yields and short reaction times.
基金partly supported by a grant of the Romanian National Authority for Scientific Research,CNDI-UEFISCDI,project number 51/2012。
文摘The effects of 4-(2-hydroxyphenyl)-2-(morpholin-4-yl)-1,3-thiazole(Pr02), 1-(3,5-dibromo-2-hydroxyphenyl)-1-oxoethan-2-yl-N,N-diethyldithiocarbamate(Pr04) and 1-(5-bromo-2-hydroxy-3-methylphenyl)-1-oxoethan-2-yl-Oethyl xanthate(Pr06) on the aqueous oxidation of chalcopyrite(CuFeS2) in air-equilibrated solution at a temperature of 25 ℃ and a pH of 2.5 were studied. The effects were investigated by using potentiodynamic polarization, electrochemical impedance spectroscopy(EIS), scanning electron microscopy coupled with energy dispersive X-ray(SEM/EDX) analysis, aqueous batch experiments, Fourier transform infrared(FTIR) spectroscopy, Raman scattering and quantum chemical calculations. It is found that the anodic current densities decrease in the order of EtOH > Pr02 > Pr04 > Pr06. These results, along with those of the EIS measurements, show that Pr02, Pr04 and Pr06 are effective anodic inhibitors of chalcopyrite aqueous oxidation. Both Raman scattering and FTIR spectroscopy indicate that the elemental sulfur, polysulfide and ferric oxyhydroxides that form on the surface of the mineral are not responsible when it comes to the aqueous oxidation inhibition of chalcopyrite. Quantum chemical calculations show that the adsorption of the tested compounds on the chalcopyrite surface is energetically favorable and so, it can explain the inhibiting effects that were observed.
文摘An efficient method is reported for the synthesis of phenacyl esters by reaction of carboxylic acids withα-bromoacetophenone promoted by potassium fluoride in ionic liquid [Bmim]PF6, the yield of the reaction is almost quantitative and the products are essentially pure.
基金Projectsupportedbythe"QinglanGongcheng"FoundationofJiangsuProvince (No .QL980 0 1)
文摘The Darzens condensation reaction of aromatic aldehydes with phenacyl chloride proceeded very efficiently in a water suspension medium in the presence of triethylbenzylammonium chloride and only trans 2,3 epoxy 1,3 diaryl 1 propanones were formed which can be isolated simply by filtration. The structures of these compounds were confirmed by elemental analysis, IR and 1H NMR spectra. Their configurations are in agreement with that of the same compounds reported in the literature. Compared to the classical Darzens condensation, this new method has the advantages of good yields, high stereoselectivity, low running cost inexpensive and environmentally benign procedure.
文摘The kinetics of SN2 reaction between phenacyl bromide and various amines in 12 different solvents were studied. Solvent effects on the rate of this reaction and free energy of activation, ΔG#, were interpreted by applying the Abraham-Kamlet-Taft (AKT) equation. The solvent polarity (π1*), solvent hydrogen-bond basicity (β1) and Hildebrand cohesive density energy (δ2H) are those parameters which increase the rate constant and decrease ΔG#, while solvent hydrogen-bond acidity (α1) will have the compensatory effect. A comparison among obtained values of second rate constants, k2 for different amines in a given solvent indicates that the amine reactivities are highly dependent on their structures. The consequent decrease of the rate constant for different amines in any given solvent was found to be: primary > secondary > tertiary. This order results from steric effects of amines.
文摘A simple and efficient synthesis of highly substituted pyrroles was achieved in water medium via multi-component strategy, using amine, DMAD/DEAD as well as phenacyl bromide catalyzed by β-CD. Utilizing this protocol various pyrrole derivatives were synthesized in good to excellent yields.
文摘An one pot method is used for the synthesis of 1,2,4,6 tetraaryl 1,4 dihydropyrazine by the reaction of phenacyl bromides with arylamines.This synthetic method provides an easier and simpler access to this kind of compounds as compared with the that in reference.
文摘The synthesis of C-substituted and N-substituted pyrrole is described by the reaction of phenacyl bromides, pentane-2, 4-dione and amine in aqueous medium using DABCO as a catalyst. The method is very convenient and applicable for alkyl as well as aryl amines and phenacyl bromides. The procedure is amenable for the synthesis of new substituted pyrroles. Moreover, aqueous medium makes the method more eco-friendly.
