SO_4^(2-)/WO_3-ZrO_2催化剂上硝基氯苯的区域选择性合成研究

Study on Regioselective Synthesis of Mononitrochlorobenzene on SO_4^(2-)/WO_3-ZrO_2 Catalysts

制备了一系列钨锆原子比不同的SO42-/WO3 ZrO2固体酸催化剂,并对其进行了表征;研究了WO3的不同含量和不同焙烧温度条件下制备的催化剂对硝酸硝化氯苯的区域选择性。结果表明:在醋酐存在下,600℃焙烧的SO42-/WO3 ZrO2(0.15)催化剂催化下,氯苯与等物质的量的硝酸反应,其产物具有强对位选择性,氯苯一硝化产物中邻/对硝基氯苯异构体的质量比达0.30,产物得率可达55.8%。该反应快速,并将对硝基化合物的绿色合成产生极其重要的影响。

A series of solid superacid catalyst of SO24/WO3ZrO2 containing different ratio of WO3 and ZrO2 have been prepared and characterized;regioselectivities of chlorobenzene mononitration with nitric acid, on these catalysts having different WO3 content and calcination temperature,were investigated.Experiments show that chlorobenzene is nitrated with high paraselectivity at present of acetic anhydride using SO24/WO3ZrO2 by a calcination step for 3 h at 600℃ as catalyst and a stoichiometric quantity of nitric acid.Nitration of chlorobenzene gives a 55.8% yield of mononitro compounds,and an orthopara isomer ratio 0.30 in product distribution of chlorobenzene mononitration.The process is rapid,and represents an attractive method for green synthesis of nitroaromatic compounds.