醇与芳胺的常压N-烷基化

染料合成中芳胺类化合物是重要的中间体,在染料的合成中往往按不同要求在氮原子上接不同的烷基,通称芳胺N-烷基化。在芳香族伯胺上氮有二个氢原子可以被进行烷基化。实践中往往需要单烷基化物,因而选择合成路线是极重要的。通常芳胺N-烷基化采用溴代烷作烷基化剂,或在硫酸催化下用醇作烷基化剂。它们反应的转化率低,选择性差,且前者原料昂贵,要损失作为反应媒介的溴素,后者反应需要加     

芳胺的N-烷基化反应

芳胺的N-烷基化产物在医药、染料、石油化工等许多领域具有广泛应用,合成方法众多,目前仍然为合成研究的热点方向,新的合成方法和反应机理研究报道频繁。笔者根据国内外已经工业化生产、目前已发表的研究文章、专利文献,总结了苯胺、对苯二胺等芳香胺的各种N-烷基化方法。     

系列烃基和烷氧基取代芳胺的合成方法研究

研究合成芳胺化合物的新路线。以简单芳胺为原料,通过铃木偶联法和傅——克烷基化法,制备一系列不同芳基和烷基取代的芳香有机胺,合成了8个目标产物。这些化合物经核磁共振氢谱和碳谱表征其结构。结果表明该合成路线经济可靠,改进后的实验操作条件简单易行。     

微波辐射合成N-芳基哌嗪盐酸盐

芳胺与N,N-双(2-氯乙基)胺盐酸盐在微波辐射下反应合成N-芳基哌嗪盐酸盐,得到一系列的重要中间体(3a～3g),所有的化合物结构经IR、1H NMR、MS表征确证。以苯基哌嗪盐酸盐的微波合成为例,考察了微波辐照时间、辐射温度、原料投料比等三个方面对苯胺转化率或主产物收率的影响。得到优化合成条件:微波辐射反应时间为20 min,微波辐射反应温度为120℃,芳胺与N,N-双(2-氯乙基)胺盐酸盐的摩尔比为1∶0.9。与传统加热方法制备N-芳基哌嗪盐酸盐相比,微波辐射下反应速度至少是常规合成方法反应速度的20倍。     

取代型N-烷基化反应专利技术综述

N-烷基化反应是合成精细化工中间体的一种重要工艺,其合成方法很多,所得产品可应用于诸多领域。其中,以卤代烷烃、烷基醇、羧酸酯、磺酸酯作为烷基化试剂的取代N-烷基化反应是非常有用的反应类型,也是近期专利申请的热点课题之一。本文对取代型N-烷基化反应专利技术进行了概述。     

芳胺的区域选择溴化反应

用5,5-二溴丙二酸亚异丙酯作溴化试剂,室温下与 N-烷基或 N,N-二烷基芳胺在二氯甲烷中反应,可区域选择地生成对位产物。产率55～93%。     

高区域选择性合成3-（芳胺）-N,N-二甲基丙酰胺衍生物

以N,N-二甲基丙烯酰胺和芳胺类化合物为原料,盐酸为促进体系,经过分子间的高区域选择性加成,成功地构建出了3-（芳胺）-N,N-二甲基丙酰胺衍生物。采用1H-NMR、13C-NMR和熔点对目标产物进行了表征。研究表明该方法具有原料便宜易得、原子经济、后处理操作简单和产品纯度高等优点,为3-（芳胺）-N,N-二甲基丙酰胺衍生物的高效、快速合成提供了一条可选的策略。     

芳胺N-单烷基化定向控制工艺进展

芳胺N-单烷基化产物是重要的精细化工产品。本文讨论了金属及其氧化物催化、沸点分子筛催化及相转移催化定向控制合成N-单烷基芳胺的方法及进展情况,并比较了各自的优缺点和发展前景。     

碳酸乙烯酯法合成N-芳基-2-噁唑烷酮

以纳米ZnO为催化剂,通过尿素的乙二醇醇解反应合成碳酸乙烯酯,实验表明:在常压下,尿素与干燥的乙二醇比例为1∶1,150℃反应8h,碳酸乙烯酯的产率为90.9%。再以碳酸乙烯酯和芳胺为原料,在Na-Y分子筛和K2CO3催化下,DMF为溶剂,回流反应3h,合成标题化合物,产率50%～85%,并利用元素分析、1HNMR、13CNMR、IR对目标化合物进行了表征。     

N-(N-乙酰基-N-芳氨基乙酰基)-N-芳氨基乙酸的合成及表征

利用芳胺和溴乙酸乙酯为原料,经过一系列反应,合成出了两个新的标题化合物,并利用IR、1HNMR对其结构进行了表征.     

Studies on the selective synthesis of N-monoalkyl aromatic amines

The intermediate Schiff base was detected by GC–MS in the reductive alkylation of nitro aromatic compounds catalysed by Raney nickel, supporting the proposed reaction mechanism. The influence of substituents and alkylating agents-alcohols on the reaction were studied and the results showed that both the position and properties of the substituents and the structures of the alcohols used have a significant effect on the N-alkylation. Steric hindrance is the main factor which inhibits N-alkylation and causes side reactions. High yields of N-monoalkyl arylamines were obtained with nitro compounds having para- or meta- substituents and with straight chain alcohols, except for methanol.     

异丙醇还原芳硝基化合物制备芳胺

制备了氧化铁、氢氧化氧铁和氢氧化氧铁/C等催化剂,并考察了其对异丙醇还原芳硝基化合物制备芳胺的催化活性。结果表明氢氧化氧铁/C的活性最高。在适宜的条件下,芳硝基化合物10mmol,异丙醇15mL,氢氧化钾0.1g,氢氧化氧铁/C0.1g,回流反应一段时间,得到芳胺的收率为35%~53%。     

Convenient and Selective Hydrogenation of Nitro Aromatics with a Platinum Nanocatalyst under Ambient Pressure

A convenient and highly selective platinum nanocatalyst was developed for the hydrogenation of nitro aromatics into the corresponding anilines at room temperature under ambient pressure. The platinum catalyst was highly active and selective for the hydrogenation of nitro aromatic compounds. Reducible groups such as aldehyde, ketone and nitrile were untouched during the hydrogenation of the corresponding nitro compounds, and the corresponding anilines were obtained quantitatively.     

取代苯胺的生物降解性研究

以BOD5／CODCr值表征有机物的生物降解性，对影响取代苯胺生物降解性的因素进行了研究，结果表明，随着浓度的升高，取代苯胺的生物降解性降低，BOD5／CODCr的对数值与浓度对数值成线性关系，在较宽的pH值范围内，部分取代苯胺的生物降解性变化不大，盐浓度的增大对取代苯胺的生物降解产生明显的抑制作用。     

羟基和氨基苯类化合物的生物氧化与代谢

引言 芳香类污染物是自然界分布广泛的一类化合物,主要来源于石油工业、造纸业、塑料加工、纤维制造以及农药生产等[1].其中大多数酚(羟基苯)和芳香胺(氨基苯)具有很强的毒性和致癌性,因此被很多国家列为首要污染物[2-3].由于物理处理法和化学处理法成本高且可能引入其他有害物质[4],人们日益关注成本低廉而处理彻底的生物法[3].     

Pt/PIC催化还原芳香硝基化合物制备芳胺

制备了一种多孔离子型高聚物(简称离聚物PIC),利用扫描电镜、透射电镜等一系列手段对离聚物PIC的形貌、结构进行表征,并制备负载型纳米铂催化剂(Pt/PIC)用于温和条件下芳胺(如对苯二胺、邻苯二胺、2-溴苯胺等)的合成实验中。实验表明:在1 atm H2条件下,该Pt/PIC催化剂对于芳香硝基化合物还原氢化反应具有高的催化活性和选择性,尤其是还原性基团如醛基、酮基、氰基,在氢化还原相应硝基芳基化合物过程中未受影响,且高产率得到相应芳胺。     

立体选择性羰基还原酶及其在手性醇合成中的应用

手性醇是重要的医药中间体与精细化工品,立体选择性羰基还原酶催化制备手性醇具有重要的研究与应用价值,受到国内外科学家和工程师的高度关注。本文主要围绕羰基还原酶的发现与分类、催化羰基还原反应的活性与立体选择性机制、酶的筛选挖掘与分子改造技术、辅酶还原型烟酰胺腺嘌呤二核苷酸（磷酸）的再生方法、羰基还原酶催化合成手性醇医药中间体与精细化学品技术开发与应用等方面展开综述。重点阐述了羰基还原酶催化制备降血脂、抗细菌或病毒感染、抗肿瘤、抗抑郁症、抗癫痫等重要疾病治疗药物中间体及脂肪族、芳香族手性醇精细化工品的国内外技术进展与应用,为高效能立体选择性生物催化剂的创制和手性化合物的生物合成提供理论借鉴和成功范例。     

Borrowing Hydrogen in the Activation of Alcohols

Alcohols can be temporarily converted into carbonyl compounds by the metal‐catalysed removal of hydrogen. The carbonyl compounds are reactive in a wider range of transformations than the precursor alcohols and can react in situ to give imines, alkenes, and α‐functionalised carbonyl compounds. The metal catalyst, which had borrowed the hydrogen, then returns it to the transformed carbonyl compound, leading to an overall process in which alcohols can be converted into amines, compounds containing C C bonds and β‐functionalised alcohols.     

FTIR Analysis of Aerosol Formed in the Photooxidation of 1,3,5-Trimethylbenzene

ABSTRACT

The composition of aerosol generated in the photooxidation of 1,3,5-trimethylbenzene was investigated in a smog chamber experiment. The relative concentrations of alcohols, carboxylic acids, organonitrates, carbonyl groups, nitroaromatics, aliphatic C—H and aromatic C—H in the aerosol were estimated through analysis of infrared spectra. Based on model compound calibrations it was estimated that a typical molecule in the aerosol contained three carbonyl groups, six aliphatic C—H bonds, and one hydroxyl group. Small amounts of organic acids (one molecule in ten) and organonitrates (one molecule in four) were observed. About 5–10 wt% of the aerosol mixture was aromatic and these structures contained nitro and hydroxyl groups. This information on aerosol chemical functionality was coupled with gas-phase chemistry mechanisms to propose potential aerosol formation pathways.     

Oxidation of primary and secondary alcohols to the corresponding carbonyl compounds with molecular oxygen using 1,1-diphenyl-2-picrylhydrazyl and WO3/Al2O3 as catalysts

The oxidation of primary and secondary alcohols to their corresponding carbonyl compounds proceeds with high efficiency under molecular oxygen in the presence of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and tungsten oxide/alumina (WO₃/Al₂O₃). The method is environmentally benign, because the reaction requires only molecular oxygen as the terminal oxidant and gives water as a side product. Various aromatic, alicyclic, and aliphatic alcohols can be converted to their corresponding carbonyl compounds in excellent yields. It is noteworthy that the oxidative transformation of the alcohols proceeds chemoselectively in the presence of other functional groups. In addition, a plausible catalytic pathway is proposed.