相转移催化法合成水杨酸苄酯

本文研究了相转移催化法合成水杨酸苄酯各反应因素对目的产物产率的影响。     

相转移催化合成醋酸苄酯

以三乙基苄基氯化铵作为相转移催化剂，对催化法合成醋酸苄酯进行了改进，降低了生产成本，减少了废物排放。醋酸苄的产率达９３．５％。     

相转移催化法制备乙酸苄酯

研究了以苯基三乙基氯化铵为相转移催化剂制备乙酸苄酯，得出了最佳操作条件，使反应收率达８６％。     

相转移催化法合成苯甲酸苄酯

相转移催化法合成苯甲酸苄酯刘永军，刘英，刘振东（曲阜师范大学化学系）１前言苯甲酸苄酯又名安息香酸苄酯，广泛存在于天然吐鲁香脂、秘鲁香酯、月下香和洋水仙中［１］，由于其具弱香味，沸点高（３２５～３２７℃），广泛用于多种花香香精的定香剂和溶剂，亦是配制人...     

利用相转移催化法合成乙酸苄酯

研究了分别以ＮａＩ／Ｅｔ３Ｎ和ＴＥＢＡＣ为相转移催化剂，以乙腈为溶剂，用相转移催化法由适量醋酸钠与氯化苄合成乙酸苄酯的方法。产率达９２－９７％。     

相转移催化合成醋酸苄酯

以三乙基苄基氯化铵作为相转移催化剂 ,对催化法合成醋酸苄酯进行了改进 ,降低了生产成本 ,减少了废物排放。醋酸苄酯的产率达 93.5 %。     

相转移催化法合成水杨酸苄酯

用相转移催化剂聚乙二醇－400催化合成水杨酸苄酯法，克服了经典合成法中的酯化时间长，反应条件苛刻等不足，收率达到83％，产物经气相色谱测定，与结构相符。     

苄醇相转移催化合成乙酸苄酯

以ＣＴＡＢ为相转移催化剂，用苄醇、冰乙酸为原料，在乙酸钠－乙酸形成的ｐＨ＝４的缓冲溶液环境下合成乙酸苄酯。以正交实验设计优化反应参数，产品红外光谱图与Ｓａｄｔｌｅｒ标准图谱完全一致。     

相转移催化合成苯甲酸苄酯

苯甲酸苄酯是白色结晶或无色粘稠液体 ,可用作麝香的溶剂 ,香精的定香剂 ,也用于配制百日咳药、气喘药等。传统的合成方法是用苯甲酸甲酯与过量的苄醇在浓硫酸的作用下发生酯交换反应 ,也有用苯甲酸钠与苄氯作用 ,但产率不理想。作者直接以苯甲酸和苄氯为原料 ,通过使用相转移催化剂 ,能获得较为满意的产率。1　反应原理COOH +CH2 Cl TBAB- Na OH- H2 O1 0 4～ 1 0 6℃ ,3hCOOCH22　苯甲酸苄酯的制备向装有电动搅拌、回流冷凝管、温度计及滴液漏斗的 50 0 m L四颈瓶中 ,加入 1 5.2 5g( 0 .1 2 5mol)苯甲酸、5g( 0 .1 2 5mol)氢氧化…     

相转移催化法合成肉桂酸苄酯

本文报道了相转移催化合成肉桂酸苄酯的新方法。将肉桂酸和氯化苄在水－氢氧化钠体系中，以四丁基氯化铵为相转移催化剂，反应制备肉桂酸苄酯。在最佳反应条件下，酯化反应时间大大缩短，酯收率达８２％。产品结构经红外光谱确证为反式构型。     

邻苯二甲酸丁苄酯的相转移催化合成

本文研究了用相转移催化剂和三相催化剂合成BBP的工艺条件。当以新洁而灭为相转移催化剂时,最佳反应条件下产物收率达97％。当以PSTB为三相催化剂时,最佳反应条件下产物收率为86％。     

BENZYL ACETATE FROM PHASE TRANSFER CATALYZED ACETATE DISPLACEMENT OF BENZYL CHLORIDE

The overall production rate equation of benzyl acetate by L-L phase transfer catalyzed acetate displacement of benzyl chloride were derived. The experimental results of the effects of stirring speed, structure and amount of catalyst, reaction temperature, amount of sodium acetate, and phase volume-ratio on the production rate of benzyl acetate are elucidated with the rate equation. Benzyltributylammonium chloride is the recommended catalyst. The apparent activation energy of the displacement of benzyl chloride with the ion pairs of benzyltributylammonium acetate is 8.13kcal/mol. Sodium sulfate is a suitable salt to improve the partition coefficient of the phase transfer catalyst. The cocatalyst, sodium iodide, can greatly improve the production rate of benzyl acetate when its amount do not exceed 3 mol% of the substrate, benzyl chloride. Under the conditions of 5mol% benzyltributylammonium chloride, phase volume-ratio 0.429, stirring speed 520 rpm, reaction temperature 70°C, and 50% aqueous sodium acetate, about 80% yield of benzyl acetate can be obtained within 2 hrs. of reaction time.     

KINETIC STUDY OF BENZYL ALCOHOL OXIDATION UNDER PHASE TRANSFER CATALYSIS CONDITIONS

In this work, benzyl alcohol oxidation to benzaldehyde by sodium hypochlorite (NaOCl) in the presence of quaternary ammonium salt was successfully carried out in an organic solvent/aqueous solution two-phase medium. An aqueous solution of low pH value is found to be favorable for the oxidation of benzyl alcohol by sodium hypochlorite. However, certain amounts of hypochlorite ions are converted to chlorines in a solution of low pH value simply by adding sulfuric acid. It is thus our goal to find a method for the production of benzaldehyde of high yield in a solution at low pH value and the prevention of chlorine production from sodium hypochlorite. Therefore, the primary purpose of this work is to search for a favorable condition for the production of benzaldehyde. It is effective to adjust the pH value by adding KCl/HCl solution rather than by adding sulfuric acid solution. Under this circumstance, the reaction follows a zero^th order rate law. Kinetics of the oxidation by sodium hypochlorite under phase transfer catalysis condition, including the effect of the agitation speed, the amount of TBAB catalyst, quaternary ammonium salts, the amount of sodium hypochlorite, the amount of sodium hydrogen carbonate, organic solvents, the pH value, the amount of dichloromethane, and the temperature on the conversion were investigated in detail. Reasonable explanations were made to satisfactorily account for the results.     

KINETIC STUDY OF BENZYL ALCOHOL OXIDATION UNDER PHASE TRANSFER CATALYSIS CONDITIONS

In this work, benzyl alcohol oxidation to benzaldehyde by sodium hypochlorite (NaOCl) in the presence of quaternary ammonium salt was successfully carried out in an organic solvent/aqueous solution two-phase medium. An aqueous solution of low pH value is found to be favorable for the oxidation of benzyl alcohol by sodium hypochlorite. However, certain amounts of hypochlorite ions are converted to chlorines in a solution of low pH value simply by adding sulfuric acid. It is thus our goal to find a method for the production of benzaldehyde of high yield in a solution at low pH value and the prevention of chlorine production from sodium hypochlorite. Therefore, the primary purpose of this work is to search for a favorable condition for the production of benzaldehyde. It is effective to adjust the pH value by adding KCl/HCl solution rather than by adding sulfuric acid solution. Under this circumstance, the reaction follows a zero^th order rate law. Kinetics of the oxidation by sodium hypochlorite under phase transfer catalysis condition, including the effect of the agitation speed, the amount of TBAB catalyst, quaternary ammonium salts, the amount of sodium hypochlorite, the amount of sodium hydrogen carbonate, organic solvents, the pH value, the amount of dichloromethane, and the temperature on the conversion were investigated in detail. Reasonable explanations were made to satisfactorily account for the results.     

相转移催化合成对硝基苯乙醚的研究

对相转移催化合成对硝基苯乙醚工艺进行了研究,通过对催化剂的选择、反应条件的优化及母液与催化剂的套用试验,讨论了影响产物质量和收率的有关因素,确定出相转移催化合成对硝基苯乙醚的最优的工艺条件.用本工艺生产的对硝基苯乙醚质量分数达99.5%以上,凝固点≥57.0?℃,收率达到95%以上.该工艺与传统的合成方法相比具有反应条件温和、反应周期短、又可省去乙醇回收、转化率和收率高且三废污染少等优点.     

相转移催化合成对硝基苯乙醚的研究

对相转移催化合成对硝基苯乙醚工艺进行了研究，通过对催化剂的选择，反应条件的优化及母液与催化剂的套用试验，讨论了影响产物质量和收率的有关因素，确定出相转移催化合成对硝基苯乙醚的最优的工艺条件，用本工艺生产的对硝基苯乙醚质量分数达99．5％以上，凝固点≥57．0℃，收率达到95％以上，该工艺与传统的合成方法相比具有反应温度、反应周期短、又可省去乙醇回收、转化率和收率高且三废污染少等优点。     

碱性介质中相转移催化氧化合成2—乙基已酸

报道了以季铵盐Q－1作相转移催化剂，在碱性介质中用高锰酸钾氧化2一乙基己醇合成2—乙基己酸的新方法。考察了催化剂种类、反应时间、物料配比、反应温度和氢氧化钠用量对产率的影响，和未加相转移催化剂的氧化反应相比，高锰酸钾用量减少20％，反应时间缩短4．0h，在本文筛选出的条件下，收率达到86.0％，具有工业应用价值。     

BENZYL ALCOHOL FROM PHASE TRANSFER CATALYZED WEAKLY ALKALINE HYDROLYSIS OF BENZYL CHLORIDE

The chemical and mass transfer processes were formulated and explained for the system initially composed of BzCl/BzR₃”NCI, R'COONa, H₂O. The effects of the size of the alkyl group of benzyltrialkylammonium chloride, the pH of the aqueous phase, the concentration of the pH controlling agent, aqueous NaOH, the stirring speed, the reaction temperature, the amounts of the cocatalysts, sodium formate and sodium acetate, and the initial volume-ratio of benzyl chloride to water on the product distribution and the production rate of benzyl alcohol were investigated experimentally.

The experimental results show that the pH of the aqueous phase is the most important factor. With sodium formate as the cocatalyst it should be controlled within 7.2-7.7, while with sodium acetate it should be within 9.5-10. Under the suitable pH and 110°C and other suitable conditions, 95% yield of benzyl alcohol can be obtained within 3 hrs of reaction time.     

微波催化合成乙酸正戊酯的研究

在微波催化条件下 ,将乙酸与正戊醇进行酯化反应 ,合成乙酸正戊酯。以正交实验设计方法确定了该合成反应的最佳条件。结果表明 :此类反应能被微波明显催化 ,致使反应速度提高60倍。     

SYNTHESIS OF DIALKOXYMETHANE AT HIGH ALKALINE CONCENTRATION VIA PHASE TRANSFER CATALYSIS

The phase-transfer catalytic reaction (PTC) of 2,4,6-tribromophenol and dibromomethane by quaternary ammonium salt was carried out in a high alkali content of KOH/dibromomethane two-phase medium. A large conversion of 2,4,6-tribromophenol is obtained at a region of high KOH content. Dibromomethane acts both as the organic-phase reactant and the organic solvent; thus, no extra organic solvent is required. Two main products, i.e., α -bromomethyl 2,4,6-tribromophenyl ether (mono-substituted product) and bis-(2,4,6-tribromophenoxide)methane (bis-substituted product), were detected in the solution during the phase-transfer catalytic reaction. The active catalyst (tetrabutylammonium 2,4,6-tribromophenoxide, ArOQ), which was produced from the reaction of 2,4,6-tribromophenol, potassium hydroxide, and tetrabutylammonium bromide (TBAB or QBr), is purified as the crystalline product from the reaction solution. A kinetic model is developed to describe the behaviors of the two organic-phase reactions on the basis of the experimental observation. The two intrinsic rate constants of the two organic-phase reactions, which are the rate-determining steps of the whole reaction system, are determined. Effects of the reaction conditions, such as agitation speed, amount of water, amount of TBAB catalyst, temperature, and amount of dibromomethane, quaternary ammonium salts, and inorganic salt KBr, on the conversion of 2,4,6-tribromophenol and the reaction rate are investigated in detail.