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1 吡啶甲酸^[1]
吡啶甲酸包括α,β,γ-三种异构体。α-吡啶甲酸称皮考啉酸,β-吡啶甲酸俗称烟酸,γ-吡啶甲酸又叫异烟酸。它们都是医药、农药和染料的中间体。异烟酸的衍生物异烟酰肼(雷米封)和异烟酰腙用做抗结核药物。烟酸存在于生物体内,它与蛋白质结合,形成辅酶,参与机体的氧化-还原作用,促进新陈代谢。动物得不到足够的烟酸不能很好制造辅酶, 相似文献
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电解氧化4-甲基吡啶合成异烟酸 总被引:8,自引:1,他引:7
以Ti基PbO2 为阳极 ,Cu或Ni为阴极 ,在硫酸介质中 ,电解氧化 4 甲基吡啶合成了异烟酸。经过实验确定的最佳合成条件为 :c(硫酸 ) =4 6 0mol/L ,c(4 甲基吡啶 ) =0 6 0mol/L ,电解电流密度i=6 0mA/cm2 ,t=6 0℃。在此条件下 ,异烟酸的收率为 6 4 6 % ,电流效率为 6 7%。同时还研究了电解过程中反应物转化率、电流效率、槽压的变化规律。经示波极谱、红外光谱和熔点测定法证明电合成的物质为异烟酸 ,质量分数为 97 7%。 相似文献
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4-甲基吡啶直接电氧化合成异烟酸工艺条件的研究 总被引:5,自引:0,他引:5
以Ti/PbO2为阳极,Pb为阴极,硫酸溶液为电解质,在阳离子交换膜为隔膜的H型电解槽中,直接电氧化4-甲基吡啶合成异烟酸,并考察了阳极电解液中4-甲基吡啶及硫酸浓度,通电量,电流密度和温度对异烟酸收率和电流效率的影响,得到的工艺条件为阳极电解液中4-甲基吡啶和硫酸的质量分数分别为10%和25%,通电量18.65(A.h),电解电流密度60 mA/cm2,60℃,在此条件下重复试验,异烟酸平均收率达到92.2%,平均电流效率50.9%。 相似文献
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烟酸的合成方法与开发前景 总被引:3,自引:0,他引:3
介绍了烟酸的性质及其在医药、食品和饲料工业中的应用,对气相氧化法(如氨氧化法、空气氧化法等)、液相氧化法(如高锰酸钾氧化法、硝酸氧化法、催化氧化法等)和电解氧化法等烟酸合成方法的优缺点及研究状况进行了评述,同时分析和评价了国内外烟酸市场的发展情况。 相似文献
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介绍了直接电氧化法和间接电氧化法制取烟酸的原料及相应的电极反应,同时对直接电氧化法制取烟酸的电解槽、电极材料、离子交换膜及支持电解质等的研究进展进行了评述。直接电氧化法多采用Pt、PbO2和PbO2/Ti为阳极,Pb和Ni为阴极,离子交换膜为隔膜,电流效率可达70%。 相似文献
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An overview of the fundamental studies on a new method of nicotinic acid synthesis by the gas phase catalytic oxidation of β-picoline by oxygen is presented. The nature of active component in vanadia catalysts and reactivity of vanadium species are considered. Common features and differences in the mechanistic steps of nicotinic acid formation on various catalysts investigated by in situ FTIR spectroscopy are discussed. Effects of the reaction mixture components on the yield of nicotinic acid are considered in detail. Attention is paid to the kinetic equations of β-picoline oxidation on vanadia-titania catalysts. 相似文献
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The oxidation of nicotinic acid and nicotinamide on a polycrystalline gold electrode occurred at almost same potentials but their reduction did at different peak potentials. The redox reaction mechanisms of nicotinic acid and nicotinamide were rationalized by the formation/disappearance of the new nitrogen-oxygen bonds in the pyridine rings by means of cyclic voltammetry and bulk electrolysis. The anodic currents of nicotinic acid and nicotinamide were controlled by diffusion, while the cathodic ones by adsorption. The difference in the cathodic peak potentials of nicotinic acid and nicotinamide on the polycrystalline gold electrode is attributed to the effect of the electron densities of remote substituents on the pyridine rings. The cathodic peak currents at about 0.20 V were linear with their concentrations in the range of 2.4 mM to 2.7 μM and 2.4 mM to 3.3 μM with detection limits of 0.27 and 0.33 μM for nicotinic acid and nicotinamide, respectively. Voltammetry was then adopted for the selective monitoring the content of nicotinic acid and nicotinamide in pharmaceuticals. 相似文献
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烟酸市场及其生产技术 总被引:9,自引:2,他引:7
目前,全球烟酸总生产规模约为4万t/a。2001年全球烟酸的需求量达3.5万t,我国烟酸需求量约5000t。国内烟酸生产技术与国外相比还有较大差距,目前尚未有大规模工业化生产烟酸的报道。本文介绍的基于氨氧化法生产烟酸的工艺,选择了适当的复合催化剂,使原料3-甲基吡啶转化率可达99%,技术水平达到国外先进水平。 相似文献
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F. D. Smith A. J. Stirton M. V. Nunez-Ponzoa 《Journal of the American Oil Chemists' Society》1966,43(8):501-504
Linear phenylalkanes made from 12, 14, 16 and 18 carbon α-olefins and benzene, with aluminum chloride or methanesulfonic acid
as the condensing agent, were found by gas-liquid chromatography of the acetophenone homologs obtained by chromic acid oxidation
to be a mixture of all possible internal position isomers.
Product distribution measured by the relative amounts of acetophenone homologs must be corrected in the case of the 2- and
3-phenylalkanes because of unequal oxidative scission and differing ease of oxidation. The 2-phenyl isomer, formed in largest
amount and presumably the highest melting isomer, was separated by low temperature crystallization from acetone.
The phenylalkane product mixtures and the isolated 2-phenyl isomers were sulfonated and detergent and surface active properties
were compared. The sodiump-alkylbenzenesulfonates from the 2-phenylalkanes were more biodegradable than the mixtures in the river water die-away test.
Presented in part at the AOCS Meeting, Cincinnati, October, 1965.
E. Utiliz. Res. Dev. Div., ARS, USDA. 相似文献