氯化铈催化合成苯甲醛乙二醇缩醛

第26卷第2期稀 Vol. 26,No.22005年4月 Chinese Rare Earths April 2005氯化铈催化合成苯甲醛乙二醇缩醛郭春燕,黄占凯,刘春生,罗根祥(辽宁石油化工大学石油化工学院,辽宁抚顺113001)摘要:以环境友好试剂氯化铈为催化剂,对苯甲醛与乙二醇的缩合反应进行了研究考察了该绿色催化剂的用量、醇醛摩尔比、带水剂等因素对苯甲醛与乙二醇缩醛收率的影响。实验结果表明,氯化铈有较好的催化活性。在回流条件下,催化剂用量约占醛用量的0.8%摩尔分数,醇醛摩尔比为1.5:1,带水剂环己烷的用量为10mL时反应120min,苯甲醛与乙二醇缩醛收率达79.6%关键词:苯甲醛乙二醇缩醛氯化铈;催化中图分类号:O614.33;0643.3文献标识码:A文章编号:1004-0277(2005)02-0019-03苯甲醛性质活泼,空气中就可缓慢氧化成苯凝管加热回流。待分水器中不再有水分出,再反应甲酸而其缩醛形式却相对稳定得多且具有优于母15分钟为止。反应结束后,并分水器中的有机层体的花果香味,因此,其缩醛的合成与应用研究日和反应液,水洗两次(每次10mL),无水MgSO4受到人们重视12。缩醛传统的合成方法是在无机燥,常压蒸馏,收集222C~228C的馏分,计算收酸[3催化下反应,但该法后处理产生大量酸性废水,率。造成环境污染。随着人们生活水平的提高和环保意识的增强,环境友好绿色催化剂的研究与应用日益2结果与讨论受到人们的关注本文探讨了以无毒无腐蚀、2.1醇醛摩尔比对缩醛收率的影响易处理的绿色路易斯酸CeCl3·7H2O7为催化剂催按实验方法取苯甲醛0.1moL,催化剂氯化铈化合成苯甲醛乙二醇缩醛,得到了满意的结果。实验.0003mol,10mL环己烷作带水剂,改变乙二醇的表明,该催化剂可使苯甲醛乙二醇缩醛收率达用量分别反应,实验结果见表1。由表1可见,乙二79.6%醇用量对收率的影响显著,增大乙二醇用量有利于1实验部分收率的提高。但当醇醛摩尔比达到1.5:1以后,收1.1主要试剂及仪器率反而有所下降,这可能是由于过量的乙二醇在催苯甲醛(分析纯,武汉有机合成化工厂);之二醇化剂存在下分子间脱水生成二氧六环副产物的缘(分析纯,沈阳试剂一厂);氯化铈(CeCl3·7H2O,分故因此最佳醇醛摩尔比为1.5:1析纯,中国医药集团上海化学试剂公司);环己烷(分析纯,沈阳沈一精细化学品有限公司); Spectrum表1醇醛摩尔比对缩醛收率的影响GX红外光谱仪(Perkin-Elmer-);wzs-1阿贝折 Table Effect of the reactant ratio on the光仪(上海)。 yield of acetalization1.2实验方法醇醛摩尔比1.2:11.3:11.4:11.5:11.6:1在50mL圆底烧瓶中,加入一定比例的苯甲收率/%49.363.166.969.067.1醛、乙二醇、催化剂和带水剂,装上分水器和回流冷20稀土第26卷2.2催化剂用量对缩醛收率的影响件同2.4,结果见表5。由表5可知,随反应时间的增改变催化剂用量,选定醇醛摩尔比为1.5:1,加,缩醛产率随之增加,但超过2h后变化不大故综其余条件同上,实验结果见表2由表2可见仅用合考虑反应时间以2h为宜少量催化剂就可获得较高收率,且随着CeCl37H2O用量增加,缩醛收率提高。当催化剂用量为苯表5反应时间对缩醛收率的影响甲醛的0.8%(摩尔分数)时具有最佳的催化效果, Table 5 Effect of reaction time on the yield因此合适的催化剂摩尔分数为0.8%。 of acetalization反应时间/min6090120150表2催化剂用量对缩醛收率的影响收率/%72.873.579.675.9 Table 2 Effect of the amount of catalysis on the yield of acetalization2.6产品的表征催化剂用量/%0.30.40.60.81.0所得产品为无色透明液体,其折射率np20=收率/%69.070.176.777.967.71.5270(文献值1.5268)。其IR(,cm-1)主要显示:3038(其环CH),2963,2889(烃CH),1608,1459(苯2.3带水剂用量对收率的影响环骨架),1225,1087(CO),757,702(一取代苯),未用量对缩醛的收率也有一定的影响,在10mL时收3结吸收峰。采用最佳醇醛摩尔比和催化剂摩尔分数,改变见羰基和羟环己烷用量,实验结果见表3。由表3可见,环己烷率最大。若环己烷用量过少,起不到较好的带水效1.稀土化合物CeCl·7H2O是一种合成苯甲果;过多则会降低反应体系的回流温度,率反而下醛环缩醛的良好催化剂具有反应条件温和,分离简降。故带水剂环己烷的用量以10mL为宜。单,产率高且无污染、无腐蚀等优点,在绿色化学进程中具有良好的应用前景。表3带水剂用量对缩醛收率的影响2.以氯化铈为催化剂合成苯甲醛乙二醇缩醛 Table 3 Effect of the amount of cyclohexane的最佳条件为:醇醛摩尔比为1.5:1,催化剂占苯 on the yield of acetalization甲醛摩尔分数的0.8%,带水剂环己烷的用量为环己烷用量/mL68910111210mL时,反应120min后苯甲醛乙二醇缩醛收率达66.477.978.079.675.673.579.6%2.4不同带水剂对缩醛收率的影响参考文献:选定带水剂用量10mL,醇醛摩尔比为1.5:[1]张克福,孙宝国苯甲醛正丁硫醇缩醛的合成研究1,催化剂摩尔分数为0.8%,改变带水剂的种类,分J].精细化工,1998,18(3):23-25.别考察环己烷、苯、甲苯、二甲苯对缩醛收率的影响,[2]田志新龚健,李菊仁,铌酸催化缩醛反应[]精细石油化工,2000,(2):23-25.实验结果见表4由表4可见,该缩合反应环己烷为3]李述文范如霖实用有机化学手册M]上海:上海科适宜的带水剂,不仅收率高,且毒性较其余三种小。技出版社,1981.319.[4]余协卿.用环境友好催化剂合成氯乙酸酯的研究[J]表4不同带水剂对缩醛收率的影响精细石油化工进展,2002,3(5):9-11.[5]罗玉梅,罗义,吕宝兰,等,磷钨酸催化合成丁酮乙二 Table 4 Effect of different water-carrying醇缩酮[J]化学推进剂与高分子材料,2003,1(5):9- agents on the yield of acetalization10.带水剂环己烷苯甲苯二甲苯[6]胥勃,吴越杂多酸(盐)一种多用途的催化剂[收率/%79.670.861.346.5化学通报,1985,(4):34-40. [7] Paquette L. A. Encylopedia of Organic Synthesis [M]. New York: John Wiley 8. Sons, 1995.1031.第2期郭春燕等:氯化铈催化合成苯甲醛乙醇缩醛21 Catalytic Synthesis of Benzaldehyde Ethylene Glycol Acetal by Cerous()Chloride Heptahydrate GUO Chun-yan, HUANG Zhan-kai, LIU Chun-sheng, LUO Gen-xiang (Petrochemical Engineering School, Liaoning University of Petroleum and Chemical Technology Fushun 113001. China) Abstract: The acetal was synthesized in high yield by the reaction of benzaldehyde with ethylene glycol in the presence of a new environmentally friendly catalyst CeCls. 7H2O. The obtained results indicated that CeCls.7H2O possessed a fairly high catalytic activity for this acetalization reaction. In this article the factors influencing the syn thesis were discussed and the best conditions were determinded. The optimum conditions are as follows: the molar atio of ethylene glycol to benzaldehyde is1.5:1 the molar ratio of catalyst to benzaldehyde is0.8%; cyclohexane better water-carrying agent to the reaction is 10 mL; reaction time is 120 min. Under the above conditions the yield of benazldehyde ethylene glycol acetal is up to 79. 6 % The results showed CeCls 7H2 O is an excellent catalyst for synthesizing benazldehyde ethylene glycol acetal. Key words: benazldehyde ethylene glycol acetal CeCl3. 7H,O:catalyst cecccecececeeecececeeeeeeceeceeeceeee eececccecececececeeeeeceeecceeceeeeeceee(上接第18页) -side cyclodextrin binding sites [JJ. J Am Chem Soc.有很好的效果,提示PACC也能水解其它含有磷酸1988110:8553-8561.二酯键的化合物如有机磷农药等并且,PAcc的配3 Condorelli Costanzo Guidi De Inhibition of体实质是能装成层析柱的琼脂糖凝胶。在实际应用 photohemolysis by copper() complexes with sod-中,利用PACC层析柱过滤含有有害磷酸酯类化合 like activity [J]. 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Preparation of the Particle of Agarose-C()Complexes and their Effects on Catalyzing the Hydrolysis of PNPP2Na YU Li-na, WANG Dong-feng, SU Lin, SUN Li-ping (Department of Food Science and Engineering Ocean University of China, Qingdao 266003, China) Abstract: The particle of agarose-Ce( complexesPACC) have been prepared using superporous agarose as supporting ligands in this paper, and the physical stability of PACC was investigated. The results indicated that PACC should been used less than 40C or pH 12.0. The PACC could also catalyze the hydrolysis of phosphate diester