甲烷磺酸铜的合成及在催化酯化反应中的性能研究

合成了甲烷磺酸铜 ,其结构经热重分析和IR表征。研究了以其催化乙酸与异戊醇酯化反应的性能及各种因素对酯化率的影响。反应条件为 :乙酸 1 67mmol,n(乙酸 )∶n(异戊醇 ) =1 .0∶1 .1 ,催化剂用量 0 .2 5 % (以酸的摩尔数计 ) ,回流反应 2 .0h ,不加带水剂 ,酯化率可达 96.0 %。其催化活性远远高于CuSO4·5H2 O ,CuCl2 ·2H2 O ,Cu(NO3 ) 2 ·3H2 O ,Cu(CH3 CO2 ) 2 ·H2 O及其它Lewis酸催化剂 ,而且反应过程中不水解 ,反应后经过简单的相分离即可重复使用 ,并成功地用于催化合成其它酯。     

酯化反应实验改进

羧酸酯的合成是高师有机化学实验中必做的实验,在实验室和工业生产中一直用硫酸作催化剂,这种传统方法硫酸用量大、副反应多、过程复杂、产品损失多,更重要的是产生大量的含酸废水污染环境,实验既费时又费力,实验效果又不够理想.为了克服这些矛盾,人们对酯化反应的催化剂进行了许多研究.例如,采用杂多酸（如H3PW12O40等）、固体超强酸（如SO2-4/ZrO2-Al2O3等）和无机盐（如FeCl3、SnCl4、Al2（SO4）3等）等作为催化剂,收到了良好效果.但这些固体酸催化剂大部分是水溶性的,重复使用性能差,因而难以实现工业化生产。近年来,固载型杂多酸作为催化剂在有机合成中的应用越来越引起人们的广泛关注 ,本文作者采用SiO2作载体,用溶胶凝胶法固载磷钨杂多酸,并用在乙酸异戊酯的合成中,已被证明是可行的.因此,我们决定将这一科研成果直接应用在实验教学中,即改革羧酸酯化实验.通过1999、2000、2001三届学生实验验证,效果良好,现就实验内容改进后加以阐述.     

新型有机锡化合物的制备及对酯化反应的催化活性

制备了2种新型有机锡化合物,并利用元素分析、红外光谱、核磁共振测试技术对其进行了表征,研究了它们对酯化反应的催化活性。结果表明,该有机锡化合物是合成酯的优良催化剂,产品收率高,饱和一元羧酸酯的收率为87%~98%,对不饱和羧酸酯和空间位阻大的叔醇酯也能得到较满意的收率,分别为90%~94%和54%~68%。有机锡化合物作为催化剂用量少,并能回收再利用。     

一种新型温敏性离子液体的合成及其对长链脂肪酸乙酯化的催化活性

合成了一种以8-羟基喹啉为阳离子,HSO^₄-为阴离子的新型离子液体(1),其结构经¹H NMR, FT-IR, ESI-MS和元素分析表征。并研究了其吸水性和溶解度等物理特性。结果表明：1不易吸水,在乙醇中溶解度呈明显的温敏特性。将1用于催化长链脂肪酸乙酯化反应,表现出较高的催化效率,其中催化棕榈酸乙酯化的产率高达95.5%。     

A New One-Pot Synthesis of Macroheterocycles Using Mannich Reaction

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从反应机理探究酯化反应教学疑问

从酸催化酯化反应机理入手,阐释试剂添加方案及同位素示踪法相关疑问。通过文献调研,以反应机理探究教材及高考试题中相关酯化反应的教学疑问,理清某些中学师生对酯化反应的模糊认识。     

Influence of Reaction Pressure on Semibatch Esterification Process of Poly(ethylene terephthalate) Synthesis

Summary: Influence of esterification pressure on oligomeric properties was studied by using a semibatch reactor. Esterification model for semibatch process was further improved by considering EG reflux in the column. It was observed that increasing the reaction pressure decreases EG/water ratio in the column while increasing the EG/TPA feed ratio increases EG/water ratio in the column. By controlling the EG reflux in a semibatch reactor, it is possible to generate oligomers with similar oligomeric properties observed at different stages of continuous process.     

球形聚萘并噁嗪树脂酸催化酯化反应

研究了球形聚萘并GFDA1嗪树脂酸催化剂的制备方法,考察了其对酯化反应的催化活性. 萘并GFDA1嗪预聚体在甲基硅油中反相悬浮固化得到球形聚萘并GFDA1嗪树脂,再经磺化反应制得聚萘并FDA1嗪树脂酸,用扫描电子显微镜及其搭载的能谱仪(EDS)考察了催化剂的外貌特征和表面主要元素分布,用Tg分析了催化剂的热稳定性,通过催化冰醋酸与乙醇酯化反应评价了催化剂的活性. 结果表明,球形聚萘并GFDA1嗪树脂在300 ℃以下不发生热失重,45 ℃磺化得到的催化剂活性最高,树脂负载磺酸基团为4.29 mmol/g. 在反应时间2 h,催化剂用量为冰醋酸质量分数的3%和n(醇):n(酸)=2:1时,冰醋酸的转化率为77%.     

赤霉素合成的研究进展

本文综述了近年来赤霉素全合成和半合成研究的进展,对有关新合成方法也作了介绍。     

The Self-catalytic Esterification Reaction of O-Phosphoryl Serine Derivative

O-Phosphoryl serine derivative can perform serf-catalytic esterification reaction in the mixture of CH3OH and CHCl3 at the room temperature. The phosphoryl group participation was the key step of the esterification. This type of reactions were proposed through an intermediate of mixed phosphoric-carboxylic anhydride that might provide a clue to the function of the phosphoryl group in the phosphorylated enzymes and in the prebiotic synthesis of protein.     

A New Method for the Esterification of Sulphonic Acids

Sulphonic acids can be smoothly converted to their methyl and ethyl esters by reaction with trimethyl and triethyl orthoformate, respectively.     

催化酯化新进展(英)

酯化是一经典的有机合成反应,随着肽合成的进展,在此领域已做了大量的研究工作。介绍了一些新的酯化有机催化剂如： Ｎ , Ｎ ′ Ｄｉｃｙｃｌｏｈ ｅｘｙｌｃａｒｂｏｄｉｉｍ ｉｄｅ, ４ｄｉｍ ｅｔｈｙｌａｍ ｉｎ ｏｐ ｙｒｉｄｉｎ ｅ, Ｂｉｓ［４（ ２, ２ｄｉｍ ｅｔｈｙｌ１, ３ｄｉｏｘｏｌｙｌ）ｍ ｅｔｈｙ ］ ｃａｒｂｏｄｉｉｍ ｉｄｅ, ｂｅｎｚｏｔｒｉａｚｏｌｙｌ Ｎ ｏｘｙｔｒｉｓｏｉｍ ｅｔｈｙｌａｍ ｉｎｏｐｈｏｓｐｈｏｎｉｕｍ 和 ２ｅｔｈ ｏｘ ｙ１（ｅｔｈ ｏｘｙｃａｒｂｏｎｙｌ）１,２ｄｉｈｙｄｒｏｑｕ ｉｎｏｌｉｎ ｅ。参考文献 ２０ 篇。     

Selective Esterification Reaction Involving Hexaalkyl Guanidinium Chloride Catalyst

A new efficient and selective esterification reaction of carboxylic acids with chloroformates is described using silica-supported catalyst (PBGSiCl). The chemioselectivity of the reaction was high particularly for sterically hindered carboxylic acids supported by a single pathway reaction.     

Kinetic Modeling of Esterification Reaction of Surfactin-C15 in Methanol Solution

Surfactin in methanol solution with acid would be spontaneously esterified into the mono- or dimethyl ester surfactin even at a temperature as low as 4 °C because there were two free carboxyl groups in the peptide loop of surfactin. Using trifluoroacetic acid as the catalyst, the esterification and the contents change in surfactin-C₁₅, mono- and dimethyl ester surfactin-C₁₅ with time were investigated at 4, 25, and 45 °C, respectively. The kinetic model was established for prediction of the esterification degree under experimental conditions. At 4, 25, and 45 °C, more than 10 % of the surfactin-C₁₅ in methanol solution in the presence of 0.05 % trifluoroacetic acid was changed into the esterified surfactin-C₁₅ after 37.6, 14.1, and 7.4 h, respectively. The maximum of intermediate of the mono-methyl ester surfactin-C₁₅ was observed at 4, 25, and 45 °C after 25, 10, and 5 days, respectively. Our results indicated that the time for preparation should be strictly controlled to avoid an unexpected esterification of surfactin during its storage and experimental treatment, and the kinetic results could be adopted as the reference condition for preparation of monomethyl ester surfactin-C₁₅.     

由Mannich反应合成新型Salen配体

以乙二胺或乙二胺衍生物为碱,与甲醛、对甲酚通过Mannich反应生成了四种N,N′-双(水杨醛)乙二胺(salen)配体,其中3个为新化合物.其结构经1H NMR,IR,MS和元素分析表征.     

Synthesis of Amphoteric Surfactants via Esterification Process

This article describes the synthesis of a novel amphoteric surfactant through esterification of 2‐hydroxy‐N,N,N‐trimethylethanaminium chloride with maleic acid alkyl ester of C₈, C₁₀, and C₁₂ chain length in the presence of base. Maleic acid alkyl esters were synthesized by the reaction of maleic anhydride with alkyl alcohol. Surface‐active properties were studied by different techniques such as surface tension and foaming property. Critical micelle concentrations (CMCs) were found by using surface tension values to learn the effect of chain length on CMC of synthesized surfactants. The best result obtained has minimal coproducts, an environmentally safer route, and a very good CMC value of surfactants.     

A New Heterocyclic Multicomponent Reaction For the Combinatorial Synthesis of Fused 3-Aminoimidazoles

When general and reliable , multicomponent reactions are among the most powerful tools in modern drug discovery. The principle of chemical ligation of reactive partners (see reaction scheme) has been employed to find a new, highly efficient synthesis of fused 3-aminoimidazoles.