Synthesis of isoamyl acetate usin NaX and NaY zeolites as catalysts

A liquid phase esterification reaction between glacial acetic acid and isoamyl alcohol has been studied using NaX and NaY zeolites as catalysts. The influence of calcination temperature, the amount of catalysts, reaction temperature, time of esterification and the molar ratio of the reactants has been investigated. Water insoluble products have been isolated from the reaction mixture and analyzed for the ester. Both NaX and NaY are found to be active as catalysts in the reaction. However, their catalytic activity varies with the reaction conditions and their calcination temperature. The reaction has been found to be 100% selective to ester formation. Catalytic activity of the zeolites has been correlated with their surface acidity.     

以固体超强酸SO4^2-／ZrO2-Fe2O3催化合成醋酸异戊酯

以合成醋酸异戊酯为探针反应,筛选出制备固体超强酸SO2-4 /ZrO2- Fe2O3 (SZF -1 )的最佳工艺条件为:ZrOCl2·8H2O9. 7g, FeCl3·6H2O16. 2g, 常温陈化24h, 0. 5mol·L-1 H2SO4 (15mL·g-1 )浸泡5h, 550℃焙烧3h。以SZF 1为催化剂合成醋酸异戊酯的反应条件为:异戊醇200mmol, n(异戊醇)∶n(醋酸) =1. 0∶1. 3, SZF -1 1g(反应物总质量的3% ), 环己烷15mL, 回流反应3h, 酯化率93. 47%。催化剂连续使用6次后酯化率仍在70%以上。     

固体超强酸SO4^2—／TiO2 催化合成异戊酸异戊酯

异戊酸异戊酯是ＧＢ2 760 - 86规定为允许使用的食用香料 ,也可微量用于化妆品、皂用香精中[1] 。异戊酸异戊酯传统合成方法为硫酸催化下由异戊酸与异戊醇直接酯化反应制得[2 ] ,由于浓硫酸易使有机物炭化、氧化 ,故副反应多、酯产物色泽深、产率受影响的诸多缺点 ,因此 ,有人开发了由异戊醇一步法合成异戊酸异戊酯的方法[3～ 5] ,但异戊酸异戊酯的收率不高 ,仅为 5 8～70 .6%。本文采用更换酯化反应催化剂的方法 ,以ＳＯ2 -4 ＴｉＯ2 固体超强酸作为催化剂 ,对异戊酸异戊酯的合成进行了研究。1　实验1 1　ＳＯ2 -4 ＴｉＯ2 固体超强酸的制…     

创新化学实验:水杨酸异戊酯的制备*

酯化反应是有机化学教学实验中最重要的实验种类,不同的酯合成方法有很大区别,这些实验培养了学生的实践能力,在教学实验的基础上,对水杨酸和异戊醇的酯化反应进行了研究探索。水杨酸异戊酯是一种前景广阔,极具开发价值的产品,研究其合成方法具有很大的潜在经济效益和社会效益。采用分水分馏方法,以环己烯为带水剂,高效合成水杨酸异戊酯,产品收率达85.9%。通过研究水杨酸异戊酯的合成方法,培养了学生独立思考的创新能力和勇于探索的科学精神,达到了良好的教学效果。     

Synthesis of （p—Substituted phenyl）azo Calix[4] arenes

A novel method for the preparation of chromogenic calixarenes with azo groups was reported.p-Substituted(-NO2,-CH3,-Cl)amilines were diazotized with isoamyl nitrite in EtONa/EtOH under refluxing condition.Fifteen mono-,bis-,tris-and tetrakis(p-substituted phenyl)azo calix[4]arenes (including proximal and distal isomers) were obtainged respectively by diazo-coupling in different molar ratio to calix[4]arenes(1) under pH=7.5-9.0 in non-aqueous solution at 0-5℃.^1H NMR and ^13C NMR spectra of (p-substtituted phenyl)azo calix[4]-arenes indicated that they existed in cone conformation in solution.     

稀土固体超强酸SO42-/TiO2/La3+催化合成丁酸异戊酯

丁酸异戊酯是无色至淡黄色透明油状液体,有近似生梨和香蕉香甜气。天然品存在于椰子油、可可豆、苹果、香蕉、葡萄、草莓等中,是我国ＧＢ２７６０－８６规定允许使用的食用香料,主要用以配制香蕉、菠萝、杏、樱桃和杂锦水果等型香精;也可用作提取天然香料的溶剂、乙酸纤维素的溶剂及增塑剂。通常它是在硫酸催化下由丁酸和异戊醉酯化反应而得［１,２］,反应时间长,副反应多,对设备腐蚀严重,废水排放量大,后处理工艺复杂。为此,本实验选用稀土固体超强酸ＳＯ４２－／ＴｉＯ２／Ｌａ３＋作为催化剂进行某些酸与异戊醇的酯化反应。 …     

Recent developments in manufacturing emulsions and particulate products using membranes

Membrane emulsification (ME) is a relatively new technique for the highly controlled production of particulates. This review focuses on the recent developments in this area, ranging from the production of simple oil-in-water (O/W) or water-in-oil (W/O) emulsions to multiple emulsions of different types, solid-in-oil-in-water (S/O/W) dispersions, coherent solids (silica particles, solid lipid microspheres, solder metal powder) and structured solids (solid lipid microcarriers, gel microbeads, polymeric microspheres, core-shell microcapsules and hollow polymeric microparticles). Other emerging technologies that extend the capabilities into different membrane materials and operation methods (such as rotating membranes, repeated membrane extrusion of coarsely pre-emulsified feeds) are introduced. The results of experimental work carried out by cited researchers in the field together with those of the current authors are presented in a tabular form in a rigorous and systematic manner. These demonstrate a wide range of products that can be manufactured using different membrane approaches. Opportunities for creation of new and novel entities are highlighted for low throughput applications (medical diagnostics, healthcare) and for large-scale productions (consumer and personal products).     

对甲苯磺酸催化合成乳酸异戊酯

报道了对甲苯磺酸在异戊醇和乳酸酯化反应中的应用 ,讨论了合成条件。实验表明其催化活性良好。     

四氯化锡催化乙酸异戊酯的合成

羧酸酯是重要的化工产品 ,其合成一直受到人们的关注 .它一般是利用羧酸、羧酸酐或酰氯与醇反应制得 ,羰基化制酯类近年也颇受重视 [1] .异戊醇是工业废料杂醇油的主要成份 ,如何合理利用是一个急需解决的问题 .一个方便的途径是使其与乙酸反应制备乙酸异戊酯 .乙酸异戊酯在香料、溶剂、萃取剂等方面都有广泛的应用 ,其传统合成方法是利用浓硫酸作为催化剂进行酯化反应 ,存在的缺点是对设备有严重的腐蚀、副产物较多、时间较长等 .四氯化锡作为高效的酯化催化剂引起了我们的注意 [2 ,3] .本文利用四氯化锡作为乙酸异戊酯的合成催化剂 ,在较…     

5-(2′-Carboxyphnyl) Azo-8-quinolinol as a Sensitive Reagent for Extractive Spectrophotometric Determination of Nickel

Abstract

A new sensitive extractive spectrophotometric method for the determination of nickel in sub-microgram level is discussed. 5-(2′-carboxyphenyl) azo-8-quinolinol reats with nickel at pH 5.2 to 6.1 to produce a wine red complex extractable in isomayl alcohol. The complex is stable for 24 hrs. Beer's law is obeyed in the range 0.04 to 0.60 ug of nickel per ml. The molar absorptivity and Sandell's sensitivity of the method are 5.5 × 10⁴1. mol^?1 cm^?1 and 0.001 μg cm^?2, respectively, at wavelength of maximum absorption (λ max 540 nm). Effects of diverse ions and variables have been studied in detail. The method has been applied to the determination of nickel in alloys like manganin, constantan, german silver, bronze, steel and in geological samples. Features of the method include high sensitivity, excelllent reproducibility and reliability.