Electrosynthesis of poly(aniline-co-p-aminophenol) having electrochemical properties in a wide pH range

Copolymerization of aniline and p-aminophenol in aqueous sulfuric acid solutions was electrochemically performed using cyclic voltammetry on platinum electrodes. The monomer concentration ratio can strongly affect the copolymerization rate and electrochemical property of the copolymer. The optimum conditions for the copolymerization are that the potential sweep covers the −0.20 to 0.95 V (vs. SCE) potential range, and that a solution contains 0.18 M aniline, 0.02 M p-aminophenol and 0.50 M H₂SO₄. A resulting copolymer synthesized under the optimum conditions has a good electrochemical activity in 0.50 M solutions of Na₂SO₄ with pH ≤ 10.0. IR and XPS spectra indicate that -OH groups and SO₄²⁻ ions are contained in the resulting copolymer. The SEM images reveal that the microstructure of the copolymer depends on the monomer concentration ratio during the electrolysis.     

L-4-溴-2-氨基丁酸的"两锅法"合成

L-蛋氨酸经过甲基化、水解和脱水关环3步"一锅法"反应得到中间体L-α-氨基-γ-丁内酯盐酸盐,收率69.0%.再与33.7%的溴化氢乙酸溶液在耐压瓶中于70℃反应9h,得到目标化合物,收率86.2%.用核磁共振氢谱和比旋光度分析对中间产物和目标产物进行了表征,还探讨了目标化合物在室温下的不稳定性及其转化机理.     

2-氨基-4-芳基噻唑的合成

以苯乙酮（对硝基苯乙酮）、硫脲和碘为原料合成了２－氨基－４－苯基噻唑和２－氨基－４－对硝基苯基噻唑。以α－卤代－２,４－二氯苯乙酮和硫脲为原料合成了２－氨基－４－（２,４－二氯苯基）噻唑。第二种合成方法反应简便,收率高     

A promising copolymer of aniline and m-aminophenol: Chemical preparation, novel electric properties and characterization

A copolymer, poly(aniline-co-m-aminophenol), was synthesized chemically. The monomer concentration ratio strongly affects the copolymerization rate and the properties of the copolymer. A solution consisting 0.34 M aniline, 0.012 M m-aminophenol, 0.47 M ammonium peroxydisulfate and 2 M H₂SO₄ was found to be an optimum mixture for the chemical copolymerization. The visible spectra show that a high concentration ratio of m-aminophenol/aniline in the mixture inhibits the chain growth of the copolymer. The spectra of IR and ¹H NMR demonstrate that m-aminophenol units are included in the copolymer chain, which play a key role in extending usable pH region of the copolymer. The result of cyclic voltammograms in a wide potential region of −0.20-0.80 V (vs. SCE) indicates that the copolymer prepared under the optimum condition still held 52.7% of the electrochemical activity when the copolymer electrode was transferred from a solution of pH 4.0 to a solution of pH 11.0, which is much better than that of polyaniline. The X-ray diffraction spectra and images of the copolymers reveal a fact that the changes in the crystal structure and morphology of the copolymers are as a function of the monomer ratio in the mixture. The conductivity of the copolymer prepared under the optimum condition is 2.3 S cm⁻¹ and slightly depends on the pH value.     

2-氨基-5-甲基苯甲酸的新合成方法

以对甲基苯胺为原料,与水合氯醛、盐酸羟胺反应制得5-甲基靛红,然后在H2O2／NaOH体系下室温反应,得2-氨基-5-甲基苯甲酸,以对甲基苯胺计,总收率为43．4％,产品经FTR,^1HNMR确证结构。     

2-氨基-4-羟基烟腈的合成

介绍了标题化合物的合成方法.以丙二腈和原乙酸三甲酯为原料,经取代、环合、水解4步反应合成目标化合物.并经MS和1HNMR对其结构进行了表征.本合成路线原料易得,操作简便,后处理方便,反应收率54.37％.     

5-(2-氨基-4-氯苯基)四氮唑的合成

4-氯-2-硝基苯甲酸用甲基磺酰胺与五氯化磷氰化,铂炭催化剂存在下加氢还原得2-氨基-4-氯苯甲腈,接着与叠氮化钠成四唑环合成5-(2-氨基-4-氯苯基)四氮唑;以4-氯-2-硝基苯甲酸计,产品总收率70%,含量99%(HPLC法),产品经IR,1HNMR,MS测定,表明结构正确。     

2-羟基-2-(4-羟苯基)乙胺盐酸盐的合成

章鱼胺在无脊椎动物神经组织中可作为神经递质、神经激素或神经调节剂，是高效、强选择性农药开发中生物合理设计的理想靶标。此外．它还具有增强人体新陈代谢和治疗神经衰弱等疾病的作用。以苯酚为原料，在无水三氯化铝存在下与氨基乙腈盐酸盐进行F—C酰基化反应，然后水解得羰基物，再用Raney镍催化加氧制得标题化合物2-羟基-2-（4-羟苯基）乙胺盐酸盐，总收率65％以上。     

Poly(2-amino-4-thiazoleacetic acid)/multiwalled carbon nanotubes modified glassy carbon electrodes for the electrochemical detection of copper(II)

Poly(2-amino-4-thiazoleacetic acid)/multiwalled carbon nanotubes modified glassy carbon electrodes obtained by electropolymerization of 2-amino-4-thiazoleacetic acid, were used for the voltammetric determination of copper ions. The voltammetric response of copper ions at poly(2-amino-4-thiazoleacetic acid)/multiwalled carbon nanotubes modified glassy carbon electrodes was evaluated by differential pulse stripping voltammetry. The peak currents were linearly dependent on the concentrations of the copper ions in the range from 7.0 × 10⁻⁷ M to 5.0 × 10⁻⁵ M, with a coefficiency of 0.9987. The detection limit is 5.0 × 10⁻¹⁰ M calculated for a signal-to-noise ratio of 3 (S/N = 3). And it could be used for the simultaneous determination of copper and cadmium ions. The proposed method was successfully applied to the determination of copper ions in natural water. The concentration of Cu²⁺ was calculated to be 2.0 × 10⁻⁵ M by standard addition method. The recovery rate was 94%.     

The electrochemical copolymerization of aniline with 2,4-diaminophenol and the electric properties of the resulting copolymer

The copolymerization of aniline and 2,4-diaminophenol (DAP) was first carried out in an acidic solution under a constant potential of 0.75 V. The copolymerization rate was found to increase with an increasing ratio of monomer DAP to aniline in the mixture. The opposite is true of the electrochemical copolymerization of aniline and o-aminophenol or m-aminophenol. The difference is due to the two kinds of electron-donating groups in DPA. Poly(aniline-co-2,4-diaminophenol) (PADAP), when synthesized under optimal conditions, has a good redox activity from pH < 1 to 11.0 in a wide potential region. Its conductivity is 0.26 S cm⁻¹, which is very close to that of polyaniline synthesized under the same conditions in the absence of DAP. The pH dependence of PADAP conductivity was found to be better than that of polyaniline. PADAP that is synthesized under optimal conditions has unique magnetic resonance properties in NMR and ESR; molecules that are synthesized in the presence of other DAP to aniline concentration ratios have different properties. The monomer concentration ratio in the mixture and the applied potential strongly affect the properties of PADAP.     

2-氨基-4-苯基噻唑的合成研究

以α-溴代苯乙酮和硫脲为原料,正丙醇为溶剂,制得2-氨基-4-苯基噻唑,通过元素分析、红外光谱、1H NMR和MS确定化合物的结构。运用正交实验筛选出最佳工艺条件:反应时间为6 h,温度为97℃(回流),α-溴代苯乙酮和硫脲摩尔比为1:1.10,2-氨基-4-苯基噻唑的产率可达97%。该方法具有安全,易控制,操作简便,后处理简单等优点,适合工业化生产。     

2-氯-3-氨基-4-甲基吡啶的合成

2 氯3 氨基4 甲基吡啶是合成抗艾滋病药物奈韦拉平的关键医药中间体。对其合成方法进行了全面的综述,并指出以4,4 二甲氧基2 丁酮和丙二腈为原料的合成方法工艺简单,生产成本低,具有较大的开发价值。     

2-苯亚甲基肼基苯甲酸-4-磺酸的合成研究

以2-氨基苯甲酸-4-磺酸为原料,经过重氮化,还原反应生成-2-羧基苯肼-5-磺酸,再与苯甲醛缩合,合成2-苯亚甲基肼基苯甲酸-4-磺酸。反应总收率约 90%。产物结构经 H1NMR和MS表征。     

2-甲基-4-氨基-5-甲酰胺甲基嘧啶的合成

以β-氨基丙腈为原料,合成2-甲基-4-氨基-5-甲酰胺甲基嘧啶(MD),并进行了结构鉴定。总收率74%,产品纯度97%以上。     

2-氨基-5-(4-甲氧苯基)-1,3,4-二唑的合成工艺研究

以对甲氧基苯甲醛为原料,通过腙化、分子内环化两步反应合成了标题化合物。实验考察了投料物质的量比,反应温度及反应时间对收率的影响,结果表明:盐酸氨基脲与对甲氧基苯甲醛的物质的量比为1.2∶1,第1步反应温度为65℃,反应时间为1.5 h,第2步反应时间为16 h,溴与1-对甲氧基苯甲亚甲基氨基脲的物质的量比为1.2∶1时为最佳反应条件,总收率68.5%。目标化合物结构经红外光谱、核磁共振氢谱及质谱等确证。     

中间体2-氨基-4-二甲氨基-6-三氟乙氧基均三嗪的合成

以三聚氯氰为原料，分别与氨水、二甲胺及三氟乙醇反应，合成2-氨基-4-二甲氨基-6-三氟乙氧基均三嗪。考察了原料配比，溶剂选择，反应时间，反应温度等因素对产品产率的影响，并通过试验得到了该反应的优化了工艺条件。胺化条件：n（三聚氯氰）：n（氨水）：n（二甲胺）=1：2：1．8～1．9，反应时间30min；醚化条件：n（2-氨基-4-二甲氨基-6-氯均三嗪）：n（氢氧化钾）：n（三氟乙醇）=1：1：1．1，反应时间2h。在此条件下，收率达到88．7％。     

Corrosion inhibition of stainless steel by polyaniline,poly(2-chloroaniline), and poly(aniline-co-2-chloroaniline) in HCl

Polyaniline (PANi), poly(2-chloroaniline) (PClANi), and poly(aniline-co-2-chloroaniline) (co-PClANi) films were synthesized by electrochemical deposition on 304-stainless steel (SS) from an acetonitrile solution. The structural properties of these polymer films were characterized by spectroscopic (FTIR and UV–vis) and electrochemical (cyclic voltammetry) methods. Open circuit potential–time (E_ocp–time) curves, potentiodynamic polarization, and electrochemical impedance (EIS) measurements showed that these films have significant protective performance against corrosion of SS in 0.5 M HCl solution. It was found that co-PClANi film has acted as a passivator as well as barrier for cathodic reduction reaction in a similar manner as PANi film. However, PClANi film has behaved only as barrier for corrosion protection of SS in 0.5 M HCl.     

(2S,3R)-2-羟基-3-氨基-4-苯基丁酸的合成方法进展

(2S,3R)-2羟基-3-氨基-4-苯基丁酸（AHPBA）是制备Bestatin、Phebestin和Probestin等氨肽酶N(Aminopeptide N)抑制剂的关键中间体。本文从氨基酸法（D-苯丙氨酸、L-天门冬氨酸、苹果酸二酯）、有机金属催化法（双功能铝配合物）、酶催化法（脂肪酶和全细胞酶）以及其它方法对此中间体的合成方法及路线进行综述和分析。经比较,有机催化法、酶法以及苯乙酮法因其具有经济有利、条件温和或路线简单特点,具有潜在的工业化应用前景。同时,未来人们对AHPBA的合成开发将集中在对已有工艺路线的改进与优化。     

4－氨基－3－苯基丁酸的合成方法

对已知的涉及合成4－氨基－3－苯基丁酸的方法进行了分类、总结,包括涉及硝基苯乙烯的Michael加成反应、以苯基戊二酸为中间体的反应、通过还原氰基或硝基的反应等,从反应原料、反应步骤、产率等方面分析了不同方法的利弊,其中,以糠氯酸为原料的方法最为新颖。为后续工作者在现有成果的基础上进行更深入的研究,寻求更为适用的合成方法提供方便。     

（NH4）2S2O8体系聚苯胺的合成及其比容量的研究

本文采用工业品原材料直接合成了导电聚苯胺，探讨了过硫酸铵体系中苯胺的聚合条件及掺杂反应时间等因素对聚苯胺比容量的影响，得出制备具有高比容量导电聚苯胺的最适宜条件为：过硫酸铵与苯胺的摩尔比为１．０，反应体系盐酸浓度为２．５ｍｏｌ／Ｌ，氧化剂滴加时间为３０ｍｉｎ，掺杂反应时间为３．５～１７．５ｈ。在此条件下可制得比容量高达１４３ｍＡｈ／ｇ的导电聚苯胺。在实验室小试基础上，我们还进行了聚苯胺的逐级放大研究，在苯胺投料量放大到７．５ｋｇ时，所得产物的比容量仍可达１２０ｍＡｈ／ｇ。