酸化蒙脱土/氯化锌催化叔丁醚和叔丁酯的合成

以酸化蒙脱土/氯化锌作为催化剂,二碳酸二叔丁酯与一系列酚、醇和羧酸类化合物在120 ℃封管条件下反应,合成了叔丁醚和叔丁酯类衍生物,方法简单,经济可靠,环境友好,后处理方便,收率为61%~75%,产物结构经¹H NMR,ESI-MS确证。 探讨了溶剂、温度、金属离子等因素对反应收率的影响,并提出了可能的反应机理。 为今后该类化合物的合成提供了一种新的方法。     

乙酸叔丁酯合成的研究

在醋酸钠存在下,由叔丁醇和乙酸酐回流酯化10h合成了乙酸叔丁酯,收率78．5％。,经元分析和IR进行了表征。     

天冬酰胺叔丁酯的改良合成

在多肽和蛋白质的结构及功能研究中,天冬酰胺(Asn)备受关注.在α-螺旋结构的肽链中,天冬酰胺往往处于C-末端,通过其侧链形成的氢键限制构象任意改变,使螺旋结构稳定[1].-CH2CONH2侧链还可作为糖肽的键合点[2],后者在细胞识别方面起着重要作用.近来又发现天冬酰胺叔丁酯与芳香醛形成亚胺后,可与另一氨基酸的酰氯缩合,生成二肽的同时伴随天冬酰胺的环化,形成四氢嘧啶酮的环状结构[3],为天冬酰胺在多肽合成中的应用开辟了新途径. 应用天冬酰胺合成多肽时,经常涉及天冬酰胺羧基的保护.甲酯和乙酯等酯基保护基在脱保护时会导致侧链脱水形成腈类副产物.叔丁酯比较稳定,在大多数形成肽键的缩合反应条件下不分解,必要时又可方便地在三氟乙酸中脱去保护,是理想的保护基.但是,叔丁酯的制备相对比较困难.由于叔丁基的空间位阻,酸催化下由叔丁醇和氨基酸直接酯化通常得不到预期的产物.采用激烈的酯化条件又可能导致氨基酸消旋化.为克服这些困难,一般以异丁烯作酯化剂,在酸催化剂存在下与氨基酸反应制备叔丁酯.……     

电荷转移聚合法合成聚丙烯酸叔丁酯的研究

本文以丙烯酸叔丁酯为单体,苯胺与二苯甲酮络合物为引发剂,四氢呋喃为溶剂,在紫外光照射下通过电荷转移聚合(CTP)合成了具有苯亚胺基链端的聚丙烯酸叔丁酯(PtBA),并用FT-IR、1H-NMR和GPC等对其进行了表征.同时考察了反应时间、引发剂浓度、反应温度等因素对单体转化率和聚合物分子量的影响.结果表明,聚合反应动力...     

N''''-叔丁胺基羰基-N-取代菊酰硫脲类化合物的合成及生物活性测定

拟除虫菊酯类和酰基硫脲类化合物具有很好的杀虫，杀菌及植物生长调节活性。本文采用有效基团拼接方法，以拟除虫菊酯类化合物的活性部分即取代菊酸为母体，以酰基硫脲为骨架，并将叔丁基引入到该结构中，设计合成了4种N-     

溴乙酸叔丁酯的简便合成法

首先以溴乙酸与氯化亚砜反应制备并分离得到溴乙酰氯,然后使其与叔丁醇在常温下反应合成溴乙酸叔丁酯．重点研究了影响酯化反应的因素,确定了酯化反应的最佳条件：三聚磷酸钠为缚酸剂,氯仿为溶剂,溴乙酰氯与叔丁醇的物质的量比1：1．15,收率93．6％．     

过氧化苯甲酸叔丁酯的热分解动力学研究及SADT推算

研究了过氧化苯甲酸叔丁酯的热分解动力学及不同包装规格下的自加速分解温度(SADT),利用C600微量热仪测试了过氧化苯甲酸叔丁酯的热分解特征,得到升温速率分别为0.1 K/min、0.2 K/min、0.5 K/min、1 K/min下热流随时间的变化曲线,并使用Friedman等转化率法对所得的实验数据进行分析处理,得到了过氧化苯甲酸叔丁酯的分解反应活化能、指前因子等热动力学参数,推算了不同包装规格的过氧化苯甲酸叔丁酯的SADT。结果表明TBPB分解活化能及指前因子随转化率变化而变化,活化能范围为42-135.5 kJ/mol,指前因子范围为0.25-33.5,在25L聚乙烯桶包装下的SADT为59℃,50L下为52℃,200L下为46℃。     

叔－丁基醚热分解反应的量子化学研究

用ＡＭ１方法研究了叔－丁基醚热分解反应，发现这类化合物可经过四元环过渡态分解成丁烯和醇或酚。     

N′-叔丁胺基羰基-N-取代菊酰硫脲类化合物的合成及生物活性测定

拟除虫菊酯类和酰基硫脲类化合物具有很好的杀虫 ,杀菌及植物生长调节活性[1 - 3] 。本文采用有效基团拼接方法 ,以拟除虫菊酯类化合物的活性部分即取代菊酸为母体 ,以酰基硫脲为骨架 ,并将叔丁基引入到该结构中 ,设计合成了 4种N 叔丁胺基羰基 N 取代菊酰硫脲类化合物。结构经1 HNMR ,IR和元素分析表征 ,初步的生物活性测定结果表明该类化合物具有较好的生物活性合成路线为 ,其结构简式如下发 :1　实验部分1 1　仪器和试剂XT4A型显微熔点测定仪 ;Nicolet5DXFT IR型红外光谱仪 (KBr压片 ) ;joelFX 90Q型超导核磁仪 (CDCl3作溶…     

SiO2/聚甲基丙烯酸叔丁酯核壳复合微粒的制备与表征

以甲基丙烯酸-3-(三甲氧基硅基)丙酯(MPS)修饰的SiO2胶体粒子为种子,甲基丙烯酸叔丁酯(tBMA)为单体、十二烷基硫酸钠(SDS)为乳化剂,采用种子乳液聚合法制备了SiO2/聚甲基丙烯酸叔丁酯的核壳复合微粒。微粒经水解后形成具有pH敏感性的无机/有机复合微粒。研究了影响核壳复合微粒形态结构的因素,结果发现,控制SiO2种子乳液的质量分数在1.5%～2%,可避免聚合过程中生成纯聚甲基丙烯酸叔丁酯乳胶粒子;反应体系中乳化剂SDS的用量超过质量分数0.3%时,易形成纯聚合物乳胶粒子;SDS用量低于质量分数0.15%时,生成的核壳复合微粒易产生团聚;单体和交联剂用量升高,核壳复合微粒的壳层厚度增加,用量过高会导致核壳复合微粒出现团聚现象,并且有纯聚合物乳胶粒子生成。采用TEM、NMR和FTIR及接触角测试技术分析结果表明,复合微粒是由SiO和聚甲基丙烯酸叔丁酯组成的核壳结构微粒。     

Method for determination of methyl tert-butyl ether in gasoline by gas chromatography

A simple method for the determination of methyl tert-butyl ether (MTBE) in gasoline has been developed. The separation of MTBE from other analytes was controlled by the use of gas chromatography–mass spectrometry in the full scan mode using the characteristic primary, secondary and tertiary ions m/z 73, 57 and 43. The sample mass spectrum did not show any superimposition of other analytes. The separation from the common gasoline component 2-methylpentane was sufficient for reliable quantitation. An application of the developed conditions using gas chromatography with flame ionization detection was performed by the analysis of regular, euro super, super premium unleaded and ‘Optimax’ gasoline from petrol stations in the area of Frankfurt/Main, Germany. Regular unleaded gasoline shows an average MTBE content of 0.4% (w/w), whereas the MTBE content in euro super gasoline varies between 0.4 and 4.2% (w/w). The blending of MTBE to super premium has increased from 8.2% (w/w) in 1998 to 9.8% (w/w) on average in 1999. The recently introduced gasoline ‘Optimax’ shows an average MTBE content of 11.9% (w/w). The presented method might also be used for the analysis of other ethers, such as ethyl tert-butyl ether, which requires the use of another internal standard.     

浓硫酸催化合成叔丁基苯

利用浓硫酸催化叔丁醇和苯的反应,得到叔丁基苯;利用正交法优化了反应条件,利用气相色谱法测定了产物收率.结果表明,将叔丁醇滴加到苯-浓硫酸混合溶液中,控制叔丁醇与浓硫酸物料摩尔比为1:1、苯的用量为50 mL、浓硫酸用量为8.0 mL、反应温度为50℃、搅拌时间为4 h,目标产物的收率可达62.0%.     

First total synthesis of isoquinolinone alkaloid marinamide and its methyl ester

The first total synthesis of isoquinolinone alkaloid marinamide 1 and its methyl ester 2 was described. The key steps involved a regioselective Frieclel-Crafts reaction of 1-benzyl-1H-pyrrole to form the intermediate 8.     

冰片及其酯/酰胺类衍生物的合成和活性研究进展

冰片是重要的芳香开窍类中药,具有开窍醒神,清热止痛等功效,常被作为佐药与其他中药配伍使用。目前,冰片及其衍生物广泛用于医药、农药、化工及香料领域,市场前景好,研究和开发价值高。本文对天然冰片、合成冰片及其酯/酰胺类衍生物的主要合成方法和生物活性方面进行了系统总结,并对冰片酯类衍生物未来的研究方向进行了展望,以期为冰片及其酯/酰胺类衍生物的进一步的研究提供有益参考。     

Synthesis of mesoporous silica and its modification of bismaleimide/cyanate ester resin with improved thermal and dielectric properties

A novel method is proposed to synthesize new mesoporous silica containing amine groups (MPSA), and it was further employed to modify bismaleimide‐dialllyl bisphenol (BD)/cyanate ester (CE) resin to form novel MPSA/BD/CE hybrids; in addition, the typical properties of MPSA/BD/CE were systematically investigated. Results show that these hybrids have very low dielectric constant and loss as well as good thermal properties. Compared with BD/CE resin, all hybrids have not only decreased dielectric constant and loss but also similar dependence of dielectric properties on frequency over the whole frequency from 10 to 10⁶ Hz. Specifically, with the addition of MPSA to BD/CE resin, the dielectric constant reduces from 3.5 to 3.0, and the dielectric loss is only 85% of that of BD/CE resin. Note that all hybrids show better thermal resistance (reflected by higher glass transition temperature, decreased maximum degradation rate, and higher char yield at 800°C) than BD/CE resin. All these differences in macro‐properties are attributed to the different structure between MPSA/BD/CE hybrids and BD/CE resin. Copyright © 2011 John Wiley & Sons, Ltd.     

Preparation and characterization of rosin glycerin ester and its bromide

Rosin glycerin ester and its bromide were prepared from natural renewable rosin, glycerin and liquid bromine which were first subjected to an esterification reaction, followed by an addition reaction. Their structures were characterized by an infrared (IR) spectrum and their thermal resistance was conducted with thermal gravity (TG) and differential scanning calorimetry (DSC). It showed that the bromide in the rosin glycerin ester decomposed faster than the ester; hence it may be used as fire-resistant material.     

吡啶与GCLE碘取代物在不同溶剂中亲核取代反应动力学研究

以7-苯乙酰氨基-3-氯甲基头孢烷烯酸对甲氧基苄酯（GCLE）和吡啶为原料合成头孢他啶中间体7-苯乙酰氨基-3-吡啶甲基头孢-4-羧酸对甲氧苄酯,用高效液相色谱仪监测了吡啶与GCLE碘取代物在二氯甲烷、丙酮、四氢呋喃、乙酸乙酯和DMF混合液中的亲核取代反应,反应的动力学行为可用SN2机理来解释。在一定的溶剂中不同温度的速率常数可用Arrhenius方程很好的关联。根据Arrhenius方程求得了指前因子,进一步讨论了该反应的溶剂效应,得出在不同溶剂中亲核取代反应顺序为：乙酸乙酯-DMF混合液＞二氯甲烷＞四氢呋喃＞丙酮。     

Kinetics of 2-methyl-2-pentene epoxidation with tert-butyl hydroperoxide

The reaction rate at the initial period during the epoxidation of 2-methyl-2-pentene with tert-butyl hydroperoxide in the presence of Mo(CO)₆ as catalyst varies linearly in the range of lower concentrations of olefin, hydroperoxide and catalyst. The reaction is losing the first order character in the region of higher concentrations due to the inhibition with the reaction products. This finds the confirmations in a discrepancy between the concentration and the instantaneous (temporal) reaction order.     

微波皂化返滴定法快速测定白酒中的总酯

研究了在密封条件下微波皂化返滴法测定白酒中总酯的各种影响因素，建立了快速测定白酒中总酯的新方法。微波功率为中档（400W），皂化时间为5min。用于3种香型白酒样品中总酯的测定，RSD≤2．6％，加标回收率为96．1％－105．9％