Optically active form of α-cyano-3-phenoxybenzyl (CPB) alcohol, building block of pyrethroid insecticides, was synthesized as its acetate by the combination of anion-exchange resin (D301)-catalyzed transcyanation bet...Optically active form of α-cyano-3-phenoxybenzyl (CPB) alcohol, building block of pyrethroid insecticides, was synthesized as its acetate by the combination of anion-exchange resin (D301)-catalyzed transcyanation between m-phenoxybenzaldehyde (m-PBA) and acetone cyanohydrin (AC), and lipase (from Alcaligenes sp.)-catalyzed enantioselective transesterification of the resulting cyanohydrin with vinyl acetate. Through optimizing technological conditions, the catalyzing efficiency was improved considerably compared to methods previously reported. Concentrations of CPB acetate were determined by gas chromatograph. The enantio excess (e.e.) values of CPB acetate were measured by NMR (nuclear magnetic resonance) method. Effects of solvents and temperatures on this reaction were studied. Cyclohexane was shown to be the best solvent among the three tested solvents. 55 °C was the optimal temperature for higher degree of conversion. External diffusion limitation was excluded by raising the rotational speed to 220 r/min. However, internal diffusion could not be ignored, since the catalyst (lipase) was an immobilized enzyme and its particle dimension was not made small enough. The reaction rate was substantially accelerated when the reactant (m-PBA) concentration was as high as 249 mmol/L, but decreased when the initial concentration of m-PBA reached to 277 mmol/L. It was also found that the catalyzing capability of recovered lipase was high enough to use several batches. Study of the mole ratio of AC to m-PBA showed that 2:1 was the best choice. The strategy of adding base catalyst D301 was found to be an important factor in improving the degree of conversion of the reaction from 20% to 80%. The highest degree of conversion of the reaction has reached up to 80%.展开更多
In this paper the two effluents from PBA (3- phenoxy -benzaldehyde) productionprocess were treated by polymeric adsorbent CHA-lll. PBA or PBC(3-phenoxybenzoic acid) was recovered from the wastewater in the process of ...In this paper the two effluents from PBA (3- phenoxy -benzaldehyde) productionprocess were treated by polymeric adsorbent CHA-lll. PBA or PBC(3-phenoxybenzoic acid) was recovered from the wastewater in the process of neutralization. As asecondary treatment method, adsorption with CHA-lll showed better efficency thanPhotocatalytic decomposition and solvent extraction. The optimal technologicalparameters were: adsorption: current velocity: 2.0 BV/hr(bed volume per hour), roomtemperature, desorption: current velocity:10 BV/hr 80℃8% sodium hydroxideaqueous solutions. In conclusion, 90.9% COD in the neutralizing wastewater and98. 4% COD in the hydrolysis wastewater are removed successfully.展开更多
3-bromo-4,5-bis(2,3-dibromo-4,5-dihydroxybenzyl)-l,2-benzenediol (1) is a natural bromophenol isolated from the red algae Rhodomela confervoides that exhibits significant inhibition against protein tyrosine phosph...3-bromo-4,5-bis(2,3-dibromo-4,5-dihydroxybenzyl)-l,2-benzenediol (1) is a natural bromophenol isolated from the red algae Rhodomela confervoides that exhibits significant inhibition against protein tyrosine phosphatase 1B (PTP1B). Based on its activity, we synthesized two new synthetic bromophenols and their methoxy derivatives from vanillin using the structure of natural bromophenol 1 as a scaffold. The structures of these bromophenols were elucidated from H NMR, 13C NMR, and high resolution electron ionization mass spectrometry as 2,3-dibromo-1-(2'-bromo-6'-(3",4"-dimethoxybenzyl)- 3 ',4 '-dimethoxybenzyl)-4,5 -dimethoxybenzene (2), 2,3-dibromo- 1 -(2 '-bromo-6'-(2 "-bromo-4",5 "-dimethoxy- benzyl)-3',4'-dimethoxybenzyl)-4,5-dimethoxybenzene (3), 3,4-dibromo-5-(2'-bromo-6'-(2"-bromo-4",5"- dihydroxybenzyl)-3',4'-dihydroxybenzyl)pyrocatechol (4) and 3,4-dibromo-5-(2'-bromo-6'-(3",4"- dihydroxybenzyl)-3',4'-dihydroxybenzyl)pyrocatechol (5). PTP1B inhibition activities of these compounds were evaluated using a colorimetric assay, and compounds 3 and 4 demonstrated interesting activity against PTP1B.展开更多
In the past few years, support vector machines (SVMs) have been applied to many fields, such as pattern recognition and data mining, etc. However there still exist some problems to be solved. One of them is that the S...In the past few years, support vector machines (SVMs) have been applied to many fields, such as pattern recognition and data mining, etc. However there still exist some problems to be solved. One of them is that the SVM is very sensitive to outliers or noises because of over-fitting problem. In this paper, a fuzzy support vector regression (FSVR) method is presented to deal with this problem. Strategies based on k nearest neighbor (kNN) and support vector data description (SVDD) are adopted to set the fuzzy membership values of data points in FSVR.The proposed FSVR soft sensor models based on kNN and SVDD are employed to predict the concentration of 4-carboxy-benzaldehyde (4-CBA) in purified terephthalic acid (PTA) oxidation process. Simulation results indicate that the proposed method indeed reduces the effect of outliers and yields higher accuracy.展开更多
A series of hexadecylphosphate acid(HDPA) terminated mixed-oxide nanoparticles have been investigated to catalyze the oxidation of toluene exclusive to benzaldehyde under mild conditions in an emulsion of toluene/wate...A series of hexadecylphosphate acid(HDPA) terminated mixed-oxide nanoparticles have been investigated to catalyze the oxidation of toluene exclusive to benzaldehyde under mild conditions in an emulsion of toluene/water with the catalysts as stabilizers. With the HDPA-Fe2 O3/Al2 O3 as the basic catalyst, a series of transition metals, such as Mn, Co, Ni, Cu, Cr, Mo, V, and Ti, was respectively doped to the basic catalyst to modify the performance of the catalytic system, in expectation of influencing the mobility of the lattice oxygen species in the oxide catalysts. Under normally working conditions of the catalytic system, the nanoparticles of catalysts located themselves at the interface between the oil and water phases, constituting the Pickering emulsion. Both the doped iron oxide and its surface adsorbed hexadecylphosphate molecules were essential to the catalytic system for excellent performances with high toluene conversions as well as the exclusive selectivity to benzaldehyde. Under optimal conditions, ~83% of toluene conversion and >99% selectivity to benzaldehyde were obtained, using molecular oxygen as oxidant and HDPA-(Fe2 O3-Ni O)/Al2 O3 as the catalyst. This process is green and low cost to produce high quality benzaldehyde from O2 oxidation of toluene.展开更多
Fe-doped ZrO2 compounds were prepared by a co-precipitation method.The compounds were characterized by X-ray diffraction,N2 adsorption-desorption,ultraviolet diffuse reflectance infrared Fourier transform spectroscopy...Fe-doped ZrO2 compounds were prepared by a co-precipitation method.The compounds were characterized by X-ray diffraction,N2 adsorption-desorption,ultraviolet diffuse reflectance infrared Fourier transform spectroscopy,scanning electron microscopy-energy-dispersive X-ray spectroscopy,transmission electron microscopy,NH3 temperature-programmed desorption,X-ray photoelectron spectroscopy,and in situ Fourier transform infrared spectroscopy.The incorporation of Fe into ZrO2 lattice favored and effectively stabilized the formation of purely ZrO2 tetragonal phase.Subsequently,the catalytic activity of the Fe-doped ZrO2 compounds was evaluated toward vapor phase methylation of phenol.The catalytic activity was governed by Fe content and related to the Lewis acidity of the prepared catalyst.展开更多
The completely selective oxidation of toluene to benzaldehyde with dioxygen,without the need touse H_(2)O_(2),halogens,or any radical initiators,is a reaction long desired but never previously successful.Here,we demon...The completely selective oxidation of toluene to benzaldehyde with dioxygen,without the need touse H_(2)O_(2),halogens,or any radical initiators,is a reaction long desired but never previously successful.Here,we demonstrate the enzyme‐like mechanism of the reaction over hexadecylphosphateacid(HDPA)‐bonded nano‐oxides,which appear to interact with toluene through specific recognition.The active sites of the catalyst are related to the ability of HDPA to change its bonding to theoxides between monodentate and bidentate during the reaction cycle.This greatly enhances themobility of the crystal oxygen or the reactivity of the catalyst,specifically in toluene transformations.The catalytic cycle of the catalyst is similar to that of methane monooxygenase.In thepresence of catalyst and through O_(2)oxidation,the conversion of toluene to benzaldehyde is initiatedat 70°C.We envision that this novel mechanism reveals alternatives for an attractive route to designhigh‐performance catalysts with bioinspired structures.展开更多
Two title compounds, 4,4?diformyl-diphenoxyethane (compound 1, C16H14O4) and 4,4?4创-triformyl-triphenoxytriethylamine (compound 2, C27H27NO6), were synthesized by condensation of 4-hydroxybenzaldehyde with 1,2-dichlo...Two title compounds, 4,4?diformyl-diphenoxyethane (compound 1, C16H14O4) and 4,4?4创-triformyl-triphenoxytriethylamine (compound 2, C27H27NO6), were synthesized by condensation of 4-hydroxybenzaldehyde with 1,2-dichloroethane and tris(2-chloroethyl)amine, respectively in dimethyl formamide in the presence of anhydrous potassium carbonate. The crystal data are: monoclinic, P21/c, a = 7.571(2), b = 12.608(3), c = 7.357(2) ? b = 105.823(6)? V = 675.7(2) 3, Mr = 270.3, Z = 2, Dc = 1.328 g/cm3, F(000) = 284, m(MoKa) = 0.096 mm-1, R = 0.0537 and wR = 0.2189 for compound 1; and monoclinic, P21/n, a = 11.7162(6), b = 9.0042(6), c = 22.908(2) ? b = 99.505(1)? V = 2383.5(3) ?, Mr = 461.50, Z = 4, Dc = 1.286 g/cm3, F(000)= 976, m(MoKa) = 0.091 mm-1, R = 0.0464 and wR = 0.1462 for compound 2. The molecule of compound 1 (dialdehyde) is located at the crystallographic inversion center nearby the midpoint of C(8)C(8A) single bond. The three chains in the molecule of compound 2 (trialdehyde) are of non-crystallographic pseudo-C3 symmetry, and each of them is quite planar.展开更多
The thermal decomposition of a new antitumor agent, 4-{5-[ 3,4-dimethyl-5-(3,4,5-trimethoxyphenyl)thiophen-2-yl ]-2-methoxyphenyl} morpholine was studied by Differential Scanning Calorimetry (DSC) and Thermogravim...The thermal decomposition of a new antitumor agent, 4-{5-[ 3,4-dimethyl-5-(3,4,5-trimethoxyphenyl)thiophen-2-yl ]-2-methoxyphenyl} morpholine was studied by Differential Scanning Calorimetry (DSC) and Thermogravimetry (TG) / Derivative Thermogravimetry ( DTG ) methods at a flow rate of nitrogen gas of 120 mL/min, The kinetic parameters were obtained from the analysis of the corresponding curves by Kissinger's method, Ozawa's method and the integral method, The results indicate that the apparent activation energy and pre-exponential constants of the decomposition reaction are 106.67 kJ/mol and 10^6.19s^-1, respectively.展开更多
The oxidation of p-xylene to terephthalic acid with molecular oxygen in acetic acids modified carbon dioxide over Co/Mn/Br catalyst was studied in a batch reactor. The results showed that the oxidation of p-xylene to ...The oxidation of p-xylene to terephthalic acid with molecular oxygen in acetic acids modified carbon dioxide over Co/Mn/Br catalyst was studied in a batch reactor. The results showed that the oxidation of p-xylene to terephthalic acid was severely inhibited when carbon dioxide exceeded a certain amount, the conversion of p-xylene decreased rapidly from 100.0% to 3.3% and the yield of terephthalic acid dropped from 42.6% to trace. Whereas the oxidation processes of p-Tolualdchyde to p-Toluic acid and 4-Carboxybenzaldehyde to tcrcphthalic acid were improved when a relative small amount of CO2 v/as added, Further investigation found that this negative effect may be caused by multiphase reactions emerging.展开更多
A new series of azo were derived from 2,5-di(p-amino phenyl)-3,6-diphenyl pyrazine in the presence of benzoic acid, salicylic acid, p-amino salicylic acid, p-methoxy phenol and pmethyl phenol. The structures of the ...A new series of azo were derived from 2,5-di(p-amino phenyl)-3,6-diphenyl pyrazine in the presence of benzoic acid, salicylic acid, p-amino salicylic acid, p-methoxy phenol and pmethyl phenol. The structures of the synthesized compounds were determined on the basis of their FTIR, UV (ultraviolet), elemental analysis and H-NMR (H-nuclear magnetic resonance) spectral date. The purity of synthesized compounds was checked by performing TLC (thin layer chromatography). The antibacterial activity was evaluated in DMSO (dimethyl sulfoxide).展开更多
Hydroxy-phenyl)-5-(2-methyl-phenyl)-6-ethoxycarbonyl-cyclohexen-2-one has been synthesized and characterized by elemental analysis, IR, UV, H NMR and MS, and its crystal 1 structure was determined by X-ray single-crys...Hydroxy-phenyl)-5-(2-methyl-phenyl)-6-ethoxycarbonyl-cyclohexen-2-one has been synthesized and characterized by elemental analysis, IR, UV, H NMR and MS, and its crystal 1 structure was determined by X-ray single-crystal diffraction method. The crystal belongs to the monoclinic system, space group P21/c with a = 14.6298(13), b = 5.8623(5), c = 22.255(2) ?, β = 105.855(2)o, V = 1836.0(3) ?3, Mr = 350.40, Z = 4, Dc = 1.268 g/cm3, F(000) = 744, μ(MoKα) = 0.086 mm-1, R = 0.0680 and wR = 0.1498. The crystal analysis results show that the cyclohexene unit of the title compound has a quasi-chair conformation, and a centrosymmetric dimer with a 16-membered ring is produced by the intermolecular hydrogen bonds.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 20336010) and the National Basic Research Program (973)of China (No. 2003CB716008)
文摘Optically active form of α-cyano-3-phenoxybenzyl (CPB) alcohol, building block of pyrethroid insecticides, was synthesized as its acetate by the combination of anion-exchange resin (D301)-catalyzed transcyanation between m-phenoxybenzaldehyde (m-PBA) and acetone cyanohydrin (AC), and lipase (from Alcaligenes sp.)-catalyzed enantioselective transesterification of the resulting cyanohydrin with vinyl acetate. Through optimizing technological conditions, the catalyzing efficiency was improved considerably compared to methods previously reported. Concentrations of CPB acetate were determined by gas chromatograph. The enantio excess (e.e.) values of CPB acetate were measured by NMR (nuclear magnetic resonance) method. Effects of solvents and temperatures on this reaction were studied. Cyclohexane was shown to be the best solvent among the three tested solvents. 55 °C was the optimal temperature for higher degree of conversion. External diffusion limitation was excluded by raising the rotational speed to 220 r/min. However, internal diffusion could not be ignored, since the catalyst (lipase) was an immobilized enzyme and its particle dimension was not made small enough. The reaction rate was substantially accelerated when the reactant (m-PBA) concentration was as high as 249 mmol/L, but decreased when the initial concentration of m-PBA reached to 277 mmol/L. It was also found that the catalyzing capability of recovered lipase was high enough to use several batches. Study of the mole ratio of AC to m-PBA showed that 2:1 was the best choice. The strategy of adding base catalyst D301 was found to be an important factor in improving the degree of conversion of the reaction from 20% to 80%. The highest degree of conversion of the reaction has reached up to 80%.
文摘In this paper the two effluents from PBA (3- phenoxy -benzaldehyde) productionprocess were treated by polymeric adsorbent CHA-lll. PBA or PBC(3-phenoxybenzoic acid) was recovered from the wastewater in the process of neutralization. As asecondary treatment method, adsorption with CHA-lll showed better efficency thanPhotocatalytic decomposition and solvent extraction. The optimal technologicalparameters were: adsorption: current velocity: 2.0 BV/hr(bed volume per hour), roomtemperature, desorption: current velocity:10 BV/hr 80℃8% sodium hydroxideaqueous solutions. In conclusion, 90.9% COD in the neutralizing wastewater and98. 4% COD in the hydrolysis wastewater are removed successfully.
基金Supported by the National Major Research Program of China"The Creation for Significant Innovative Drugs"(No.2009ZX09103-148)the Natural Science Foundation of Shandong(No.BS2009YY011)+1 种基金the Natural Science Foundation of Qingdao(No.10-3-4-8-2-JCH)the Program of Qingdao Shinan District(No.2009-HY-2-14)
文摘3-bromo-4,5-bis(2,3-dibromo-4,5-dihydroxybenzyl)-l,2-benzenediol (1) is a natural bromophenol isolated from the red algae Rhodomela confervoides that exhibits significant inhibition against protein tyrosine phosphatase 1B (PTP1B). Based on its activity, we synthesized two new synthetic bromophenols and their methoxy derivatives from vanillin using the structure of natural bromophenol 1 as a scaffold. The structures of these bromophenols were elucidated from H NMR, 13C NMR, and high resolution electron ionization mass spectrometry as 2,3-dibromo-1-(2'-bromo-6'-(3",4"-dimethoxybenzyl)- 3 ',4 '-dimethoxybenzyl)-4,5 -dimethoxybenzene (2), 2,3-dibromo- 1 -(2 '-bromo-6'-(2 "-bromo-4",5 "-dimethoxy- benzyl)-3',4'-dimethoxybenzyl)-4,5-dimethoxybenzene (3), 3,4-dibromo-5-(2'-bromo-6'-(2"-bromo-4",5"- dihydroxybenzyl)-3',4'-dihydroxybenzyl)pyrocatechol (4) and 3,4-dibromo-5-(2'-bromo-6'-(3",4"- dihydroxybenzyl)-3',4'-dihydroxybenzyl)pyrocatechol (5). PTP1B inhibition activities of these compounds were evaluated using a colorimetric assay, and compounds 3 and 4 demonstrated interesting activity against PTP1B.
基金National Key Technologies Research and Development Program in the 10th five-year plan,国家杰出青年科学基金
文摘In the past few years, support vector machines (SVMs) have been applied to many fields, such as pattern recognition and data mining, etc. However there still exist some problems to be solved. One of them is that the SVM is very sensitive to outliers or noises because of over-fitting problem. In this paper, a fuzzy support vector regression (FSVR) method is presented to deal with this problem. Strategies based on k nearest neighbor (kNN) and support vector data description (SVDD) are adopted to set the fuzzy membership values of data points in FSVR.The proposed FSVR soft sensor models based on kNN and SVDD are employed to predict the concentration of 4-carboxy-benzaldehyde (4-CBA) in purified terephthalic acid (PTA) oxidation process. Simulation results indicate that the proposed method indeed reduces the effect of outliers and yields higher accuracy.
基金supported by the National Natural Science Foundation of China(91434101,91745108)the Ministry of Science and Technology of the People’s Republic of China(2017YFB0702900)~~
文摘A series of hexadecylphosphate acid(HDPA) terminated mixed-oxide nanoparticles have been investigated to catalyze the oxidation of toluene exclusive to benzaldehyde under mild conditions in an emulsion of toluene/water with the catalysts as stabilizers. With the HDPA-Fe2 O3/Al2 O3 as the basic catalyst, a series of transition metals, such as Mn, Co, Ni, Cu, Cr, Mo, V, and Ti, was respectively doped to the basic catalyst to modify the performance of the catalytic system, in expectation of influencing the mobility of the lattice oxygen species in the oxide catalysts. Under normally working conditions of the catalytic system, the nanoparticles of catalysts located themselves at the interface between the oil and water phases, constituting the Pickering emulsion. Both the doped iron oxide and its surface adsorbed hexadecylphosphate molecules were essential to the catalytic system for excellent performances with high toluene conversions as well as the exclusive selectivity to benzaldehyde. Under optimal conditions, ~83% of toluene conversion and >99% selectivity to benzaldehyde were obtained, using molecular oxygen as oxidant and HDPA-(Fe2 O3-Ni O)/Al2 O3 as the catalyst. This process is green and low cost to produce high quality benzaldehyde from O2 oxidation of toluene.
文摘Fe-doped ZrO2 compounds were prepared by a co-precipitation method.The compounds were characterized by X-ray diffraction,N2 adsorption-desorption,ultraviolet diffuse reflectance infrared Fourier transform spectroscopy,scanning electron microscopy-energy-dispersive X-ray spectroscopy,transmission electron microscopy,NH3 temperature-programmed desorption,X-ray photoelectron spectroscopy,and in situ Fourier transform infrared spectroscopy.The incorporation of Fe into ZrO2 lattice favored and effectively stabilized the formation of purely ZrO2 tetragonal phase.Subsequently,the catalytic activity of the Fe-doped ZrO2 compounds was evaluated toward vapor phase methylation of phenol.The catalytic activity was governed by Fe content and related to the Lewis acidity of the prepared catalyst.
文摘The completely selective oxidation of toluene to benzaldehyde with dioxygen,without the need touse H_(2)O_(2),halogens,or any radical initiators,is a reaction long desired but never previously successful.Here,we demonstrate the enzyme‐like mechanism of the reaction over hexadecylphosphateacid(HDPA)‐bonded nano‐oxides,which appear to interact with toluene through specific recognition.The active sites of the catalyst are related to the ability of HDPA to change its bonding to theoxides between monodentate and bidentate during the reaction cycle.This greatly enhances themobility of the crystal oxygen or the reactivity of the catalyst,specifically in toluene transformations.The catalytic cycle of the catalyst is similar to that of methane monooxygenase.In thepresence of catalyst and through O_(2)oxidation,the conversion of toluene to benzaldehyde is initiatedat 70°C.We envision that this novel mechanism reveals alternatives for an attractive route to designhigh‐performance catalysts with bioinspired structures.
基金The authors thank the financial support of the Natural Science Foundation of Fujian Province (No. E0110010)
文摘Two title compounds, 4,4?diformyl-diphenoxyethane (compound 1, C16H14O4) and 4,4?4创-triformyl-triphenoxytriethylamine (compound 2, C27H27NO6), were synthesized by condensation of 4-hydroxybenzaldehyde with 1,2-dichloroethane and tris(2-chloroethyl)amine, respectively in dimethyl formamide in the presence of anhydrous potassium carbonate. The crystal data are: monoclinic, P21/c, a = 7.571(2), b = 12.608(3), c = 7.357(2) ? b = 105.823(6)? V = 675.7(2) 3, Mr = 270.3, Z = 2, Dc = 1.328 g/cm3, F(000) = 284, m(MoKa) = 0.096 mm-1, R = 0.0537 and wR = 0.2189 for compound 1; and monoclinic, P21/n, a = 11.7162(6), b = 9.0042(6), c = 22.908(2) ? b = 99.505(1)? V = 2383.5(3) ?, Mr = 461.50, Z = 4, Dc = 1.286 g/cm3, F(000)= 976, m(MoKa) = 0.091 mm-1, R = 0.0464 and wR = 0.1462 for compound 2. The molecule of compound 1 (dialdehyde) is located at the crystallographic inversion center nearby the midpoint of C(8)C(8A) single bond. The three chains in the molecule of compound 2 (trialdehyde) are of non-crystallographic pseudo-C3 symmetry, and each of them is quite planar.
基金SUPPORTED BY THE NATIONAL YOUNG SCHOLAR AWARD OF NSFC( NO. 30125043 ).
文摘The thermal decomposition of a new antitumor agent, 4-{5-[ 3,4-dimethyl-5-(3,4,5-trimethoxyphenyl)thiophen-2-yl ]-2-methoxyphenyl} morpholine was studied by Differential Scanning Calorimetry (DSC) and Thermogravimetry (TG) / Derivative Thermogravimetry ( DTG ) methods at a flow rate of nitrogen gas of 120 mL/min, The kinetic parameters were obtained from the analysis of the corresponding curves by Kissinger's method, Ozawa's method and the integral method, The results indicate that the apparent activation energy and pre-exponential constants of the decomposition reaction are 106.67 kJ/mol and 10^6.19s^-1, respectively.
文摘The oxidation of p-xylene to terephthalic acid with molecular oxygen in acetic acids modified carbon dioxide over Co/Mn/Br catalyst was studied in a batch reactor. The results showed that the oxidation of p-xylene to terephthalic acid was severely inhibited when carbon dioxide exceeded a certain amount, the conversion of p-xylene decreased rapidly from 100.0% to 3.3% and the yield of terephthalic acid dropped from 42.6% to trace. Whereas the oxidation processes of p-Tolualdchyde to p-Toluic acid and 4-Carboxybenzaldehyde to tcrcphthalic acid were improved when a relative small amount of CO2 v/as added, Further investigation found that this negative effect may be caused by multiphase reactions emerging.
文摘A new series of azo were derived from 2,5-di(p-amino phenyl)-3,6-diphenyl pyrazine in the presence of benzoic acid, salicylic acid, p-amino salicylic acid, p-methoxy phenol and pmethyl phenol. The structures of the synthesized compounds were determined on the basis of their FTIR, UV (ultraviolet), elemental analysis and H-NMR (H-nuclear magnetic resonance) spectral date. The purity of synthesized compounds was checked by performing TLC (thin layer chromatography). The antibacterial activity was evaluated in DMSO (dimethyl sulfoxide).
基金This work was financially supported by the Education Committee of Hunan Province (02C465)Hunan Provincial Key Discipline and Hunan Provincial General College Leader of Learning
文摘Hydroxy-phenyl)-5-(2-methyl-phenyl)-6-ethoxycarbonyl-cyclohexen-2-one has been synthesized and characterized by elemental analysis, IR, UV, H NMR and MS, and its crystal 1 structure was determined by X-ray single-crystal diffraction method. The crystal belongs to the monoclinic system, space group P21/c with a = 14.6298(13), b = 5.8623(5), c = 22.255(2) ?, β = 105.855(2)o, V = 1836.0(3) ?3, Mr = 350.40, Z = 4, Dc = 1.268 g/cm3, F(000) = 744, μ(MoKα) = 0.086 mm-1, R = 0.0680 and wR = 0.1498. The crystal analysis results show that the cyclohexene unit of the title compound has a quasi-chair conformation, and a centrosymmetric dimer with a 16-membered ring is produced by the intermolecular hydrogen bonds.