对二甲苯与羟胺盐反应体系的产物调控规律  

Regulating Product Distribution for Reaction of p-Xylene with Hydroxylamine Salts

作　　者：王延吉[1] 檀学军[1] 徐元媛 高丽雅[1] 张东升[1] 

机构地区：[1]河北工业大学化工学院,绿色化工与高效节能河北省重点实验室,天津300130

出　　处：《化学反应工程与工艺》2012年第5期405-411,共7页Chemical Reaction Engineering and Technology

基　　金：国家自然科学基金(21236001、21106029、21176056);973计划前期研究专项(2010CB234602);天津市自然科学基金(12JCQNJC03000);河北省自然科学基金(B2012202043);2012年河北省高等学校科学研究计划(Q2012034)

摘　　要：以钼化合物为催化剂,考察了对二甲苯与羟胺盐体系一步合成2,5-二甲基苯酚或2,5-二甲基苯胺的反应.探讨了反应介质、催化剂加入量、反应温度以及时间等因素对该体系反应产物的影响.结果发现,当反应介质为体积比4∶10∶1的水-乙酸-硫酸溶液,催化剂加入量为0.5 g,羟胺/对二甲苯的物质的量之比为1～1.2之间,温度80℃、时间4h的反应条件下,对二甲苯-羟胺盐体系可以生成2,5-二甲基苯酚产物,其选择性为83％.另外,在反应介质为体积比10∶5～13∶2的乙酸-硫酸溶液,对二甲苯使用量为20 mmol,催化剂加入量为0.25 g,反应温度为85℃,反应时间为4h的条件下,对二甲苯-羟胺盐体系可以高选择性地生成2,5-二甲基苯胺,其选择性为88％.One-pot synthesis of 2,5-xylenol or 2,5-xylidine from p-xylene and hydroxylamine salts catalyzed by molybdenum compounds was studied. The influences of various reaction parameters such as reaction media, catalyst amount, reaction temperature and time were examined systematically. The results show that p-xylene can be hydroxylated by hydroxylamine to produce 2,5-xylenol with a selectivity of 83%, and the optimum reaction condition is as follows： H20-HAc-H2SO4 as reaction media with volume ratio of 4：10：1, catalyst amount of 0.5 g, NH2OH/p-xylene molar ratio of 1 to 1.2：1, reaction temperature of 80 ℃ and reaction time of 4 h. On the other hand, 2,5-xylidine will be produced with a higher selectivity of 88% from the same reactant system ofp-xylene and hydroxylamine salts, and the optimum reaction condition is HAc-HESO4 as reaction media with volume ratio of 10：5 to13：2,p-xylene amount of 20 mmol, catalyst amount of 0.25 g, and conducting reaction at 85 ℃ for 4 h.

关 键 词：对二甲苯羟胺钼2 5-二甲基苯酚2 5-二甲基苯胺 

分 类 号：TQ243.1[化学工程—有机化工] TQ246.3