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2^#胺在锌浮选上的工业应用
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作者 韩潮 金恒儒 刘学胜 《有色矿冶》 北大核心 1989年第2期21-22,28,共3页
2~#胺是胺类和多聚胺类混合物。沈阳矿冶研究所利用化纤厂废料研制的由辽阳文圣化工厂生产的2#胺是有效的价格便宜的浮选扑收剂。绥中矿石加工厂应用2#胺作锌浮选扑收剂代替丁基黄药,半年生产实践证明使用2#胺锌精矿品位和回收率略... 2~#胺是胺类和多聚胺类混合物。沈阳矿冶研究所利用化纤厂废料研制的由辽阳文圣化工厂生产的2#胺是有效的价格便宜的浮选扑收剂。绥中矿石加工厂应用2#胺作锌浮选扑收剂代替丁基黄药,半年生产实践证明使用2#胺锌精矿品位和回收率略好于使用丁基黄药。2#胺价格是丁基黄药价格的三分之一,同时2#胺有起泡性能,对黄铁矿扑收能力弱。山于有这些特点,生产使用2#胺可节省起泡剂和石灰用量。绥中矿石加工厂处理每吨矿可降低药剂费用0.95元/吨。2#胺是棕红色硷性粘液加水稀释有沉淀物析出易堵塞药管,这是其主要缺点,克服这一缺点2#胺应用将更加广泛。 展开更多
关键词 2^# 浮选
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Synthesis of 3-Chloro-2-Nitrotoluene
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作者 冯荣秀 宋健 +3 位作者 陈磊 马丽 张静 孙国鹏 《Transactions of Tianjin University》 EI CAS 2002年第1期40-42,共3页
The synthesis of 3 chloro 2 nitrotoluene using 2,6 dichloroaniline as starting material by diazotization, substitution, condensation, decarboxylic reaction was studied and the best conditions of the synthetic proc... The synthesis of 3 chloro 2 nitrotoluene using 2,6 dichloroaniline as starting material by diazotization, substitution, condensation, decarboxylic reaction was studied and the best conditions of the synthetic procedures were confirmed. Dichloronitrobenzene was obtained in 78.9% yield based on 2,6 dichloroaniline. The reaction of 2,6 dichloronitrobenzene and methyl cyanoacetate with potassium carbonate catalyst in N,N dimethyl formamide gave methyl 2 cyano 2 (3′ chloro 2′ nitrophenyl) acetate in 80.2% yield. The third procedure product 3 chloro 2 nitrophenylacetic acid was obtained by hydrolysis in 82.6% yield. Decarboxylation reaction of 3 chloro 2 nitrophenylacetic acid produced 3 chloro 2 nitrotoluene in 72.9% yield.The structure of products was identified by IR and NMR. 展开更多
关键词 chloro 2 nitrotoluene 2 6 dichloroaniline SYNTHESIS
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Nicotinamide overload may play a role in the development of type 2 diabetes 被引量:8
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作者 Shi-Sheng Zhou Da Li +19 位作者 Wu-Ping Sun Ming Guo Yong-Zhi Lun Yi-Ming Zhou Fu-Cheng Xiao Li-Xin Jing Shen-Xia Sun Li-Bin Zhang Ning Luo Fu-Ning Bian Wei Zou Lai-Bin Dong Zhi-Gang Zhao Sheng-Fan Li Xiao-Jie Gong Zeng-Guo Yu Chang-Bin Sun Cong-Long Zheng Dong-Ju Jiang Zheng-Ning Li 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第45期5674-5684,共11页
AIM: To investigate whether nicotinamide overload plays a role in type 2 diabetes. METHODS: Nicotinamide metabolic patterns of 14 diabetic and 14 non-diabetic subjects were compared using HPLC. Cumulative effects of... AIM: To investigate whether nicotinamide overload plays a role in type 2 diabetes. METHODS: Nicotinamide metabolic patterns of 14 diabetic and 14 non-diabetic subjects were compared using HPLC. Cumulative effects of nicotinamide and N^1-methylnicotinamide on glucose metabolism, plasma HzO2 levels and tissue nicotinamide adenine dinucleotide (NAD) contents of adult Sprague-Dawley rats were observed. The role of human sweat glands and rat skin in nicotinamide metabolism was investigated using sauna and burn injury, respectively. RESULTS: Diabetic subjects had significantly higher plasma N^1-methylnicotinamide levels 5 h after a 100-mg nicotinamide load than the non-diabetic subjects (0.89 ± 0.13 μmol/L vs 0.6 ± 0.13 μmol/L, P 〈 0.001). Cumulative doses of nicotinamide (2 g/kg) significantly increased rat plasma Nl-methylnicotinamide concentrations associated with severe insulin resistance, which was mimicked by Nl-methy-Inicotinamide. Moreover, cumulative exposure to N^1- methylnicotinamide (2 g/kg) markedly reduced rat muscle and liver NAD contents and erythrocyte NAD/ NADH ratio, and increased plasma H2O2 levels. Decrease in NAD/NADH ratio and increase in H2O2 generation were also observed in human erythrocytes after exposure to N^1-methylnicotinamide in vitro. Sweating eliminated excessive nicotinamide (5.3-fold increase in sweat nicotinamide concentration 1 h after a 100-mg nicotinamide load). Skin damage or aldehyde oxidase inhibition with tamoxifen or olanzapine, both being notorious for impairing glucose tolerance, delayed N^1- methylnicotinamide clearance. CONCLUSION: These findings suggest that nicotinamide overload, which induced an increase in plasma N^1- methylnicotinamide, associated with oxidative stress and insulin resistance, plays a role in type 2 diabetes. 展开更多
关键词 Type 2 diabetes NICOTINAMIDE N^1-methyl-nicotinamide Insulin resistance Oxidative stress Liver Sweat glands
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Experimental and Density Functional Theory Calculation Studies on Raman and Infrared Spectra of 1,1'-Binaphthyl-2,2'-diamine 被引量:1
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作者 Zhen-lin Zhang Wen-lou Wang +1 位作者 Shi-lin Liu Dong-ming Chen 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2017年第1期7-15,I0001,共10页
The IR absorption, visible excited normal Raman, and UV-excited near-resonant Raman (UVRR) spectra of 1,1'-binaphthyl-2,2'-diamine (BINAM) were measured and analyzed. Density functional theory calculations were ... The IR absorption, visible excited normal Raman, and UV-excited near-resonant Raman (UVRR) spectra of 1,1'-binaphthyl-2,2'-diamine (BINAM) were measured and analyzed. Density functional theory calculations were carried out to investigate its vibrational frequencies, infrared absorption, normal Raman, and near-resonance Raman intensities. The observed Raman and IR bands of BINAM were assigned with respect to the local vibrations of substituted 2-naphthylamine. Several Raman bands of BINAM were found selectively enhanced in the UVRR in comparison with the normal Raman spectrum. Possible excited state geometry distortion was discussed based on the resonance Raman intensity analysis. 展开更多
关键词 1 1'-Binaphthyl-2 2'-diamine Resonance Raman INFRARED Density functional theory Molecular vibrations
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Synthesis and Crystal Structure of (C_6N_3H_(18))_2Ti_4O_4(C_2O_4)_7·4H_2O
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作者 孙巧珍 张汉辉 +5 位作者 黄长沧 王永净 孙瑞卿 陈义平 曹彦宁 郭文军 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2004年第9期989-992,共4页
The title compound (C6N3H18)2Ti4O4(C2O4)74H2O 1 (C13H22N3O18Ti2, Mr = 604.14) was synthesized by the reaction of Ti(SO4)2, H2C2O42H2O and N-(2-ammonioethyl)- piperazinium (AEPP) in aqueous solution. The single-crystal... The title compound (C6N3H18)2Ti4O4(C2O4)74H2O 1 (C13H22N3O18Ti2, Mr = 604.14) was synthesized by the reaction of Ti(SO4)2, H2C2O42H2O and N-(2-ammonioethyl)- piperazinium (AEPP) in aqueous solution. The single-crystal X-ray analysis has revealed that 1 crystallizes in the triclinic system, space group Pi with a = 9.1437(6), b = 11.4991(10), c = 11.6975(8) ? a = 96.2915(18), ?= 107.998(3), ? = 104.276(4), V = 1110.35(14) ?, Z = 2, Dc = 1.807 g/cm3, F(000) = 618, ?= 0.815 mm-1, the final R = 0.0463 and wR = 0.1264 for 3718 observed reflections with I > 2s(I). X-ray crystal-structure analysis suggests that compound 1 consists of [Ti4O4(C2O4)7]6- anion and two protonated N-(2-ammonioethyl)piperazinium cations. The anions are linked into an infinite chain through Ti4O4(C2O4)8 by sharing the oxalates as bridging ligands. 展开更多
关键词 TITANIUM CHAIN N-(2-ammonioethyl)-piperazinium oxalic acid
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Selective arylation/annulation cascade reactions of 2-alkynylanilines with diaryliodonium salts
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作者 段英 杨艳良 +1 位作者 戴晓玉 李东密 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第11期1837-1840,共4页
An efficient Cu catalyzed selective arylation/annulation cascade reaction of 2-alkynylanilines with diaryliodonium salts was developed.This reaction was selective to N-arylation instead of C-arylation,which provides a... An efficient Cu catalyzed selective arylation/annulation cascade reaction of 2-alkynylanilines with diaryliodonium salts was developed.This reaction was selective to N-arylation instead of C-arylation,which provides a simple synthetic method for N-aryl indoles. 展开更多
关键词 Selective arylation ANNULATION Diaryliodonium salt 2-Alkynylaniline N-Aryl indole Cascade reaction
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Synthesis and Crystal Structure of 4-Salicylimine-3, 5-bis(2-hydroxyphenyl)-1, 2, 4-triazole JI Bao-Minga 被引量:4
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作者 JI Bao-Ming DU Chen-Xia +1 位作者 ZHU Yu WANG Yang 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2002年第3期252-255,共4页
The title compound, 4-salicylimine-3, 5-bis(2-hydroxyphenyl)-1, 2, 4-triazole, was obtained by the condensation reaction of 4-amino-3, 5-bis(2-hydroxyphenyl)-1, 2, 4-triazole with salicylaldehyde in methanol. The crys... The title compound, 4-salicylimine-3, 5-bis(2-hydroxyphenyl)-1, 2, 4-triazole, was obtained by the condensation reaction of 4-amino-3, 5-bis(2-hydroxyphenyl)-1, 2, 4-triazole with salicylaldehyde in methanol. The crystal structure (C21H16N4O3, Mr = 372.38) belongs to monoclinic system, space group P21/n with a = 10.507(2), b = 16.878(3), c = 11.199(2) ? = 110.86(3), V = 1855.9(6) ?, Z = 4, Dc = 1.333 g/cm3, F(000) = 776, (MoK? = 0.092 mm-1, R = 0.0552 and wR = 0.1095 for 1920 reflections ( I > 2.0(I) ). The analytical results of crystal structure show that there are two different non-covalent interactions in the compound. One is hydrogen bond, and the other p-p stacking interaction. These two types of non-covalent interactions play an important role in the packing of crystal. 展开更多
关键词 TRIAZOLE hydrogen bond crystal structure stacking interaction
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C-H…O Hydrogen Bonds and π…π Interaction and the Crystal and Molecular Structures of 3-Nitro-benzylideneaniline-methyl-2’ 被引量:1
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作者 胡志辉 黄忠林 张德纯 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2004年第4期376-380,共5页
The title compound (C14H12N2O2, Mr = 240.26) crystallizes in the monoclinic system, space group P21/a with a = 7.394(1), b = 21.334(3), c = 7.423(1) ? b = 89.82(1)? V = 1170.8(3) ?, Z = 4, Dc = 1.363 g/cm3, m(MoKa) = ... The title compound (C14H12N2O2, Mr = 240.26) crystallizes in the monoclinic system, space group P21/a with a = 7.394(1), b = 21.334(3), c = 7.423(1) ? b = 89.82(1)? V = 1170.8(3) ?, Z = 4, Dc = 1.363 g/cm3, m(MoKa) = 0.93 cm-1 and F(000) = 504.00. The final R and wR are 0.0440 and 0.1370 for 2153 observed reflections (I > 2s(I)), respectively. The dihedral angle between the two phenyl rings is 52.9 and that between the NO2 group and its attached ring is 3.0. In the crystal, molecules are stacked along [100] through p…p interactions. The CH…O hydrogen bond (3.403 ? 120.4? laterally connects the stacks along [010] to form networks (001) which are further anti- parallelly connected by CH…O (3.382 ? 142.9) and p…p interactions extending along [001]. Also presented here is a brief study on the CH…O hydrogen bonds in nitro-substituted benzyl-ideneanilines which can be classified into five types, namely, )5(12R, )4(21R, )8(22R, )6(12R and )7(22R, with the first three occurring more often. 展开更多
关键词 nitro-benzylideneaniline-methyl-2 Schiff base C-H…O hydrogen bonds π…π interaction molecular structure crystal structure
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Catalytic role of Cu(I) species in Cu_2O/CuI supported on MWCNTs in the oxidative amidation of aryl aldehydes with 2-aminopyridines 被引量:4
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作者 H. N. Hareesh K. U. Minchitha +1 位作者 N. Nagaraju N. Kathyayini 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2015年第11期1825-1836,共12页
Cu2O and Cul were supported on multiwalled carbon nanotubes (MWCNTs) using a wet impregna- tion method, and the resulting materials were fully characterized by powder X-ray diffraction, Fourier transform infrared sp... Cu2O and Cul were supported on multiwalled carbon nanotubes (MWCNTs) using a wet impregna- tion method, and the resulting materials were fully characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy, transmission electron microscopy, and temperature-programmed desorption with ammonia analysis. The results of these experiments revealed that Cu2O and CuI were deposited on the MWCNTs in the cubic and γ phases, respectively. These results also showed that the Cu-containing MWCNTs exhibited weak to strong electron-accepting (Lewis acidic) properties. The catalytic activities of these materials were studied for the synthesis of biologically significant N-(pyridin-2-yl)benzamides via the oxidative amidation of aryl aldehydes with 2-aminopyridines. The yields of the products were in the range 50%-95% with 100% selectivity. Notably, the CuI/MWCNT catalyst was much more effective than the Cu2O/MWCNT catalyst with respect to the isolated yield of the product, although the latter of these two catalysts exhibited much better recyclability. A preferential interaction was observed between the polar nature of the acid-activated MWCNTs and the ionic Cu2O compared with covalent CuL The differences in these interactions had a significant impact on the rate of the nucleophilic attack of the amino group of 2-aminopyridine substrate on the carbonyl group of the aryl aldehyde. 展开更多
关键词 Cuprous oxide Cuprous iodide Multiwalled carbon nanotube2-Aminopyridine Oxidative amidation
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Determination of 2-Amino-6-Cyclopropylamino-9-(2,3-Dideoxy-β-D-glyceropent-2-enofuranosyl)purine in Rat Plasma,Urine and Liver Homogenates by High Performance Liquid Chromatography
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作者 刘薏 杨振军 +2 位作者 Boudinot F Douglas CHU Chang Kuang 张礼和 《Journal of Chinese Pharmaceutical Sciences》 CAS 2003年第2期93-97,共5页
Aim To develop a simple and specific high-performance liquid chromatographic(HPLC) method, suitable for the pharmacokinetic studies in vivo, to determine the concentrations of2-amino-6-cyclopropylamino-9-(2,3-dideoxy-... Aim To develop a simple and specific high-performance liquid chromatographic(HPLC) method, suitable for the pharmacokinetic studies in vivo, to determine the concentrations of2-amino-6-cyclopropylamino-9-(2,3-dideoxy-β-D-glyceropent-2-enofuranosyl)purine (Cyclo-D4G, IMGprodrug) in rat plasma, urine and liver homogenates. Methods Chromatography was performed with C-18Hypersil ODS column and a mobile phase of 7% (v/v) acetonitrile in phosphate buffer, pH 7.40, withUV detection at 283 nm. Results The average extraction recovery of Cyclo-D4G in rat plasma and urinewas 100.1% over its linear range of 0.5 - 80 μg·mL^(-1). The accuracy of the assay was 99.4% .The intra-and inter-day RSDs were less than 9.0% . Conclusion The analytical method was found to beapplicable, reliable and suitable for pharmacokinetic studies. 展开更多
关键词 pharmaceutical analysis HPLC analysis D4G prodrug stability
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Crystal Structure and Electrochemical Behavior of Copper Complex with 6-Hydroxymethyl-substituted Tris(2-pyridylmethyl) Amine, [CuCl(C_(19)H_(20)N_4O)]ClO_4
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作者 高云玲 彭孝军 +4 位作者 孙世国 孙立成 陈昌能 刘秋田 黄德光 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2004年第11期1262-1265,共4页
A Cu(II) complex [CuCl(C19H20N4O)]ClO4 1 containing hydroxymethyl substituted TPA (TPA = tris(2-pyridylmethyl)amine) was prepared. It crystallizes in monoclinic, space group P21/c with a = 11.7628(2), b = 13.0083(3), ... A Cu(II) complex [CuCl(C19H20N4O)]ClO4 1 containing hydroxymethyl substituted TPA (TPA = tris(2-pyridylmethyl)amine) was prepared. It crystallizes in monoclinic, space group P21/c with a = 11.7628(2), b = 13.0083(3), c = 15.11280(10) ?, β = 108.724(2)°, V = 2190.09(7) ?3, Mr = 518.83, Z = 4, T = 293(2) K, Dc = 1.574 g/cm3, μ = 1.280 mm-1, F(000) = 1060 and S = 1.085. The final R = 0.0543 and wR = 0.1433 for 2693 observed reflections with I >2σ(I). The penta- coordinated copper (II) complex assumes an approximate square pyramidal geometry. Cyclic volta- mmetry measurement of the complex showed a quasi-reversible CuII/CuI redox couple with E1/2 = –0.467 v and ?E = 68 mv. 展开更多
关键词 copper complex substituted TPA cyclic voltammetry
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Synthesis and Crystal Structure of a New Hexadentate Ligand N,N'-Bis(di(2-pyridyl)methyl)ethylenediamine
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作者 YEBao-Hui CHENXiao-Ming 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2004年第3期242-246,共5页
The reaction of di(2-pyridyl)ketone with ethylenediamine produced hexadentate Schiff base 1 which can be reduced to form a new ligand N,N-bis(di(2-pyridyl)-methyl)ethylene- diamine (BDPM) in ethanol solution. The two ... The reaction of di(2-pyridyl)ketone with ethylenediamine produced hexadentate Schiff base 1 which can be reduced to form a new ligand N,N-bis(di(2-pyridyl)-methyl)ethylene- diamine (BDPM) in ethanol solution. The two compounds were characterized by elemental analyses and spectroscopic methods. Their structures were determined by X-ray diffraction study. Crystal data for 1: C24H20N6, Mr = 392.5, monoclinic, P21/c, a = 13.871(3), b = 13.510(2), c = 12.153(2) ? b = 112.97(2)? Z = 4, V = 2094.1(6) ?, Dc = 1.245 g/cm3, m(MoKa) = 0.078 mm-1, F(000) = 824, the final R = 0.0545 and wR = 0.0557 for 2048 observed reflections (I > 2s(I)); for BDPM: C24H24N6, Mr = 396.49, monoclinic, C2/c, a = 21.411(3), b = 8.053(1), c = 11.868(1) ? b = 92.63(1)? Z = 4, V = 2044.2(4) 3, Dc = 1.288 g/cm3, m(MoKa) = 0.080 mm-1, F(000) = 840, the final R = 0.0401 and wR = 0.0939 for 1673 observed reflections (I > 2s(I)). 展开更多
关键词 synthesis crystal structure hexadentate ligand di-2-pyridyl ketone
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Ultrasonic study on molecular interactions in binary mixtures of formamide with 1-propanol or 2-propanol
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作者 Manju Rani Suman Gahlyan +1 位作者 Ankur Gaur Sanjeev Maken 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第4期689-698,共10页
Ultrasonic speeds have been measured at 298.15 K and 308.15 K for mixtures of formamide + 1 -propanol or 2-propanol. For an equimolar mixture, excess molar compressibility follows the sequence of l-propanol 〉 2-prop... Ultrasonic speeds have been measured at 298.15 K and 308.15 K for mixtures of formamide + 1 -propanol or 2-propanol. For an equimolar mixture, excess molar compressibility follows the sequence of l-propanol 〉 2-propanol. The ultrasonic speed data are correlated by various correlations such as Nomoto's relation, van Dael's mixing relation and impedance dependence relation, and analyzed in terms of Jacobson's free length theory and Schaaffs collision factor theory. Excess isentropic compressibility is calculated from ex- perimental ultrasonic speed data and previously reported excess volume data. The excess molar ultrasonic speed and isentropic compressibility values are fitted to Redlich-Kister polynomial equation. Other proper- ties such as molecular association, available volume, free volume, and intermolecular free length are also calculated. The excess isentropic compressibility data are also interpreted in terms of graph theoretical ap- proach. The calculated isentropic compressibility values are well consistent with the experimental data. It is found that the interaction between formamide and propanol increases when hydroxyl group attached to a carbon atom has more -CH3 groups. 展开更多
关键词 Ultrasonic speedGraph theoretical approachFormamidePropanollntermolecular interaction
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Synthesis and Crystal Structure of 2-[(4-Methoxy- 6-methylthio-2-pyrimidinyl)aminocarbonyl- aminosulfonyl] Benzoic Acid Methyl Ester
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作者 黄明智 王晓光 +2 位作者 毛春晖 黄路 宋海斌 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2004年第7期743-746,共4页
The title compound 2-[(4-methoxy-6-methylthio-2-pyrimidinyl)aminocarbonyl- aminosulfonyl]benzoic acid methyl ester (C15H16N4O6S2, Mr = 412.44) was obtained by the reaction of (4-methoxy-6-methylthio-2-pyrimidinyl)amin... The title compound 2-[(4-methoxy-6-methylthio-2-pyrimidinyl)aminocarbonyl- aminosulfonyl]benzoic acid methyl ester (C15H16N4O6S2, Mr = 412.44) was obtained by the reaction of (4-methoxy-6-methylthio-2-pyrimidinyl)amine with 2-methoxylcarbonylbenzene-sulfonylisocya- nate. The crystal is of monoclinic, space group P21/c with a =11.169(3), b = 9.508(3), c = 17.690(5) ? b = 91.593(5), Z = 4, V = 1877.9(10) 3, Dc = 1.459 g/cm3, F(000) = 856, m(MoKa) = 0.324 mm-1, R = 0.0690 and wR = 0.1368 for 3301 observed reflections (I > 2s(I)). The N(1)H…N(3) and N(2)H…O(4) hydrogen bonds can be observed. In the molecule the phenyl plane(I), pyrimi- din-2-yl-urea bridge plane(Ⅱ) and ester plane(Ⅲ) form three conjugated systems. 展开更多
关键词 crystal structure sulfonylurea herbicide 2-[(4-methoxy-6-methylthio-2- pyrimidinyl)aminocarbonylaminosulfonyl]benzoic acid methyl ester SYNTHESIS
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Hydrolysis Kinetics of 2-Pyridinecarboxamide, 3-Pyridinecarboxamide and 4-Pyridinecarboxamide in High-Temperature Water
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作者 傅杰 任浩明 +1 位作者 祝巨 吕秀阳 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2014年第9期1005-1008,共4页
A kinetic study is reported here on hydrolysis of three pyridinecarboxamides in high-temperature water in the temperature range of 190-250℃ at 8 MPa. 2-Pyridinecarboxamide, 3-pyridinecarboxamide and 4-pyridinecarboxa... A kinetic study is reported here on hydrolysis of three pyridinecarboxamides in high-temperature water in the temperature range of 190-250℃ at 8 MPa. 2-Pyridinecarboxamide, 3-pyridinecarboxamide and 4-pyridinecarboxamide hydrolyze to corresponding picolinic acids. 2-Picolinic acid is further decarboxylated to pyridine. Experiments at different temperatures show that the first-order rate constants display an Arrhenius behavior with activation energies of (110.9 ±2.3), (70.4 ± 2.1) and (61.4 ± 1.8)kJ.mo1-1 for 2- pyridinecarboxamide, 3-pyridinecarboxamide and 4-pyridinecarboxamide, respectively. These kinetic parameters for pyridinecarboxamide hydrolysis are more reliable and accurate than those from the consecutive hydrolysis of cyanopyridines. 展开更多
关键词 High-temperature waterHydrolysisPyridinecarboxamideKineticsActivation energy
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Synthesis and characterization of 2-hydroxy-N-methyl-N-phenyl-acetamide
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作者 周忠诚 舒万艮 《Journal of Central South University of Technology》 2002年第1期25-29,共5页
2-hydroxy N methyl N phenyl acetamide was synthesized by using N methylaniline, chloracetyl chloride, anhydrous sodium acetate and methanol through the acetylation, esterfication and ester interchange steps. The acety... 2-hydroxy N methyl N phenyl acetamide was synthesized by using N methylaniline, chloracetyl chloride, anhydrous sodium acetate and methanol through the acetylation, esterfication and ester interchange steps. The acetylation of N methylaniline with chloracetyl chloride, catalyzed by triethylamide with mole ratio n (C 6H 5NHCH 3)∶ n (ClCH 2C(O)Cl)∶ n (N(C 2H 5) 3)=1∶1.05∶1, the yield of 2 chloro N methyl N phenyl acetamide(Ⅰ) was 93.8%; Then the esterification of Ⅰ with anhydrous sodium acetate in the presence of phase transfer catalyst tetrabutyl ammonia bromide gave 97.3% yield of 2 acetoxyl N methyl N phenyl acetamide (Ⅱ); The ester interchange of with methanol catalyzed by potassium hydroxide gave 2 hydroxy N methyl N phenyl acetamide (Ⅲ) in 96.4% yield. And the total yield was 88.0%. IR and MS spectroscopy of products were analyzed and their characteristic peaks were assigned. Combining the results of elemental analysis, the molecular structure of Ⅰ, Ⅱ and Ⅲ was identified. 展开更多
关键词 -N-methyl N phenyl acetamide synthesis ACETYLATION esterfication ester interchange characterization
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Iron contributes to the formation of catechol isoquinolines and oxidative toxicity induced by overdose dopamine in dopaminergic SH-SY5Y cells
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作者 王冉 庆宏 +2 位作者 刘晓茜 郑晓琳 邓玉林 《Neuroscience Bulletin》 SCIE CAS CSCD 2008年第3期125-132,共8页
Objective The selective loss of dopaminergic neurons in Parkinson's disease is suspected to correlate with the increase of cellular iron, which may be involved in the pathogenesis of PD by promotion of oxidative stre... Objective The selective loss of dopaminergic neurons in Parkinson's disease is suspected to correlate with the increase of cellular iron, which may be involved in the pathogenesis of PD by promotion of oxidative stress. This research investigated dopamine-induced oxidative stress toxicity contributed by iron and the production of dopamine-derived neurotoxins in dopaminergic SH-SYSY cells. Methods After the SH-SYSY cells were pre-incubated with dopamine and Fe^2+ for 24 h, the cell viability, hydroxyl radical, melondialdehyde, cell apoptosis, and catechol isoquinolines were measured by lactate dehydrogenase assay, salicylic acid trapping method, thiobarbuteric acid assay, Hoechst 33258 staining and HPLC-electrochemical detection (HPLC-ECD), respectively. Results (1) Optimal dopamine (150 μmol/L) and Fe^2+ (40 or 80 μmol/L) significantly increased the concentrations of hydroxy radicals and melondialdehyde in SH-SYSY cells. (2) Induction with dopamine alone or dopamine and Fe^2+ (dopamine/Fe^2+) caused cell apoptosis. (3) Compared with untreated cells, the catechol isoquinolines, salsolinol and N-methyl-salsolinol in dopamine/Fe^2+-induced cells were detected in increasing amounts. Conclusion Due to dopamine/Fe^2+-induced oxidative stress similar to the state in the parkinsonian substantia nigra neurons, dopamine and Fe^2+ impaired SH-SYSY cells could be used as the cell oxidative stress model of Parkinson's disease. The catechol isoquinolines detected in cells may be involved in the pathogenesis of Parkinson's disease as potential neurotoxins. 展开更多
关键词 Parkinson's disease Fe^2 DOPAMINE oxidative stress SALSOLINOL N-methyl-salsolinol
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Hydrophobic intensification flotation:Comparison of collector containing two minerophilic groups with conventional collectors 被引量:14
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作者 Sheng LIU Guang-yi LIU +1 位作者 Yao-guo HUANG Hong ZHONG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2020年第9期2536-2546,共11页
The surface hydrophobization and flotation of a xanthate−hydroxamate collector toward copper oxide mineral were compared with the combined collectors of xanthate and hydroxamate through water contact angle(WCA)and mic... The surface hydrophobization and flotation of a xanthate−hydroxamate collector toward copper oxide mineral were compared with the combined collectors of xanthate and hydroxamate through water contact angle(WCA)and micro-flotation experiments.The results showed that S-[(2-hydroxyamino)-2-oxoethyl]-O-octyl-dithiocarbonate ester(HAOODE)exhibited stronger hydrophobization and better flotation performance to malachite(Cu2(OH)2CO3)than octyl-hydroxamic acid(OHA)and its combination with S-allyl-O-ethyl xanthate ester(AEXE).To understand the hydrophobic intensification mechanism of HAOODE to malachite,zeta potential,atomic force microscopy(AFM)and XPS measurements were carried out.The results recommended that malachite chemisorbed HAOODE to form Cu—HAOODE complexes in which the hydroxamate—(O,O)—Cu and—O—C(—S—Cu)—S—configurations co-existed.The co-adsorption of HAOODE’s hetero-difunctional groups was more stable than the single-functionalgroup adsorption of OHA and AEXE,which produced the“loop”structure and intensified the self-assembly alignment of HAOODE on malachite surfaces.In addition,the“h”shape steric orientation of the double hydrophobic groups in HAOODE facilitated stronger hydrophobization toward malachite than the“line”or“V”hydrophobic carbon chains of OHA or AEXE.Thus,HAOODE achieved the preferable flotation recovery of malachite particles in comparison with OHA and AEXE. 展开更多
关键词 S-[(2-hydroxyamino)-2-oxoethyl]-O-octyl-dithiocarbonate ester atomic force microscopy(AFM) heterodifunctional co-adsorption HYDROPHOBIZATION malachite flotation
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BF_(3)·OEt_(2)Mediated Intramolecular Cyclization of 2-Alkynylanilines Approach to 3-Sulfenylindoles
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作者 Gao Yushen Gao Yuanyuan +5 位作者 Zhang An'an Li Lu Geng Weizhi Zhang Fenghua Li Fei Liu Lantao 《有机化学》 SCIE CAS CSCD 北大核心 2024年第9期2785-2795,共11页
3-Sulfenylindoles are widely found in natural products,bioactive molecules and organic functional materials.BF_(3)·OEt_(2)mediated electrophilic cyclization reaction of 2-alkynylaniline with N-(arylthio)succinimi... 3-Sulfenylindoles are widely found in natural products,bioactive molecules and organic functional materials.BF_(3)·OEt_(2)mediated electrophilic cyclization reaction of 2-alkynylaniline with N-(arylthio)succinimide was developed leading to the efficient synthesis of various biologically active 3-sulfenylindoles in moderate to high yields under very mild conditions.This protocol has the advantages of broad scope,functional group diversity,mild conditions and ease of operation.Moreover,gram-scale preparation portends the practical application. 展开更多
关键词 2-alkynylaniline electrophilic cyclization metal-free catalysis 3-sulfenylindole
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Synthesis and Crystal Structure of Carvedilol
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作者 CHEN Wei-Min XU Ji-Hong ( Institute of Pharmaceutical Sciences, the First Military Medical University,Guangzhou, 5l05l5) +3 位作者 ZENG Long-Mei ( Department of Chemistry, Zhongshan University ,Guangzhou 51O275) YU Kai-Bei ( Chengdu Institue of Analysis 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 1998年第5期325-328,共4页
The crystal structure of the title compound carvedilol, C24H25N2O4(Mr= 406. 47), has determined by single-crystal X-ray diffraction. The crystal is mono-clinic with space group P21/c, a=9. 094(l), b= l2. 754(1), c= 18... The crystal structure of the title compound carvedilol, C24H25N2O4(Mr= 406. 47), has determined by single-crystal X-ray diffraction. The crystal is mono-clinic with space group P21/c, a=9. 094(l), b= l2. 754(1), c= 18. 330(2) A, β=97. 36(1 )°, V= 2l08. 5(4) A 3, Z= 4, D.= l. 280 g/cm3, F(000) = 864, μ=O. O88mm-1 and final R= O. O368, wR(F2) = 0.0787 for reflections (I>2σ(I) ). X-ray anal-ysis reveals that the crystal is composed of a pair of enantiomer, and there are hydrogenbonds O(3) -H(3O) -N(l ) between the two enantimers. There are two planes in themolecule. 展开更多
关键词 CARVEDILOL SYNTHESIS crystal structure
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