相转移催化合成对硝基苯乙醚

用相转移催化剂合成了对硝基苯乙醚,优选了原料配比,反应温度和时间,克服了乙醇对硝基的还原作用,获得质量较好的产品。含量测定用气相色谱分析。并进行了高压液相色谱分析。     

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。     

相转移催化合成邻硝基苯乙醚的研究

以邻硝基氯苯、氢氧化钠、乙醇为原料,在相转移催化剂的条件下合成了邻硝基苯乙醚。采用了各种不同的相转移催化剂,主要包括季铵盐、聚乙二醇(PEG)及季铵盐与聚乙二醇两者的复配,对比考察了催化剂种类和用量对邻硝基苯乙醚反应收率的影响,确定了最佳催化剂及反应工艺条件,并且在搅拌器型式上进行了改进。实验结果表明,四丁基溴化铵具有最佳催化活性,邻硝基苯乙醚的收率为82.8%,色谱纯度为99.0%。     

相转移催化合成对硝基苯甲醚

评述了聚乙二醇、聚苯乙烯固载聚乙二醇树脂、季铵盐、聚苯乙烯固载季铵盐树脂、氯化聚氯乙烯固载三乙胺树脂、聚苯乙烯固载吡啶树脂、聚氯乙烯固载吡啶树脂、聚氯乙烯固载多乙烯多胺树脂和聚苯乙烯固载三乙醇胺树脂催化合成对硝基苯甲醚的方法。     

相转移催化法合成对氟硝基苯

在几种不同季铵盐存在下,采用氟化钾氟化钠混合氟化剂(对氯硝基苯与混合氟化剂的比为1:1.5 mol,对氯硝基苯与氟化钾的比为1:1 mol)合成了对氟硝基苯,研究了催化剂、反应时间和反应温度对产率的影响。     

聚乙二醇相转移催化法制备对硝基苯甲醚

研究了对硝基氯苯在聚乙二醇相转移催化荆作用下合成对硝基苯甲醚,考察了甲醇用量及碱用量对反应过程的影响,并用薄板层析法追踪反应时间,红外光谱法表征产物结构.     

三相相转移催化合成对硝基苯甲醚的研究

合成制备了聚苯乙烯支载聚乙二醇 ,并以之作为三相相转移催化剂用于对硝基氯苯合成对硝基苯甲醚 ,考察了催化剂、NaOH、CH3OH等的用量对反应转化率的影响 ,得到了适宜的合成工艺条件为 :n(PCNB)∶n(CH3OH)∶n(NaOH)∶n(PTC) =1∶3∶3∶(0 0 3～ 0 0 5) ,反应温度约 78～ 80℃ ,反应时间 9～ 1 0h。在该条件下 ,对硝基氯苯转化率大于 99 5 % ,收率大于 95 % ,产品经气相色谱检测纯度达 99 7% ,聚苯乙烯支载聚乙二醇催化剂可重复使用 5次以上 ,反应母液经除盐后 ,配碱套用对反应无不良影响     

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。     

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％。     

相转移催化法制备醋酸苄酯

本文报导制备醋酸苄酯的新方法。以季铵盐Q—1作为相转移催化剂,使用结晶醋酸钠(NaAc·3H_2O)和氯化苄制备醋酸苄酯。反应物摩尔比为NaAc·3H_2O:PhCH_2Cl:Q-1=1.25:1:0.05,回流反应2h,醋酸苄酯的收率为89％,纯度大于99％。相转移催化剂可反复使用。     

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.     

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.     

固-液相转移催化法合成蛋氨酸

本文以甘氨酸酯为原料,经醛亚胺化、固－液相转移催化烃化合成了蛋氨酸。该法具有原料易得,反应条件温和、操作简单等特点。     

STUDY OF THE REACTION OF GLYCINE AND BENZOYL CHLORIDE UNDER INVERSE PHASE TRANSFER CATALYSIS

This study examined the feasibility of reacting benzoyl chloride (PhCOCl) and sodium glycinate (H₂NCH₂COOH) catalyzed by 4-dimethylaminopyridine (DMAP) in an alkaline (NaOH) aqueous solution/dichloromethane two-phase medium. This catalyzed reaction of benzoyl chloride and sodium glycinate was described by a pseudo-first-order rate law. The hydrolysis of benzoyl chloride in the two*phase reaction was neglected on the specified reaction conditions. In addition, the effects of operating conditions on the conversion of benzoyl chloride and the reaction rate. According to those results, the reaction rate decreases with an increasing concentration of benzoyl chloride, which contradicts the general rate law of reaction kinetics, This peculiar phenomenon could be accounted for altering the interfacial property due to the change of the chemical property of reactants and intermediate, and the interaction between reactants and intermediate which was transferred from organic phase to aqueous phase.