文档介绍：摘要
季戊四醇缩酮在有机合成与工业生产中有广泛的应用。在19世纪时,人们就已经开始对它们的合成进行研究。季戊四醇缩酮的合成是由季戊四醇与酮在酸催化下缩合而成。可以通过选择反应物的物料比、溶剂、催化剂合成双缩酮、单缩酮、杂二缩酮。本文将对季戊四醇缩酮合成的研究作进一步说明。实验结果表明:物料配比n (季戊四醇)∶n(酮)为1∶2,催化剂为十二钨磷酸或对氨基苯磺酸,其中催化剂十二钨磷酸的制备的最佳条件为钨酸钠和磷酸氢二钠的配比为12:1,pH为2,最佳反应温度为90℃。两种催化剂用量均为0·7 g,带水剂为环己烷,用量80 mL。在最佳工艺条件下所制得的产品为白色片状晶体。以十二钨磷酸为缩酮反应的催化剂, 杂多酸作为酸型催化剂,是近年来发现的较为理想的酸型催化剂。具有较高的催化性能,酮与季戊四醇的反应为非均相催化,其催化活性不受回收次数的影响。以对氨基苯磺酸为缩酮反应的催化剂,具有较高的活性与选择性,连续催化性能好,后处理简便,副反应少等优点,是一种很有开发前景的固体酸催化剂。通过红外谱图对产品进行了物性和结构表征。
关键词:季戊四醇;缩酮;合成;催化
Abstract
Pentaerythritol ketal has a wide application anic synthesisand industrial production. In the 19th century, people had already started their synthesis of research. The synthesis of pentaerythritol ketal acid-catalyzed condensation of pentaerythritol and ketone. Materials to select reactants, solvents, catalysts ketal, single ketal, mixed the two acetal ketone. This article will pentaerythritol shrink ketone synthesis for further instructions. Experimental results show that: material ratio n (pentaerythritol): n (ketone) is 1:2, the catalyst for 12 tungstophosphoric acid or sulfanilic acid, the best conditions of preparation of the catalyst 12 tungsten phosphate sodium tungstate and disodium hydrogen phosphate ratio of 12:1, pH 2, the reaction temperature is 90 ℃. The amount of the two catalysts are 0 ? 7 g, dehydrating agent is cyclohexane, the amount of 80 mL. The products obtained under the optimum conditions for the white flaky crystals. 12 tungstophosphoric acid ketal reaction catalyst, heteropoly acid as the acid catalyst, is the ideal acid catalyst discovered in recent years. With high catalytic performance, reaction of ketones with pentaerythritol as non-homogeneous catalysis, and its catalytic activity is not the number of recovered. Sulfanilic acid for the reduction of the ketone catalyst has high activity and selectivity, continuous catalytic performance, post-processing simple and less side effects on the advantages of solid acid catalyst is a useful development prosp