胺基烷基磺酸内鎓盐催化甲苯氯甲基化反应

制备了7种胺基烷基磺酸内盐相转移催化剂,以多聚甲醛和盐酸为氯甲基化试剂,研究了该类催化剂催化甲苯氯甲基化反应的情况。考察了催化剂类型、催化剂用量、反应温度、反应时间及盐酸用量对甲苯氯甲基化反应的影响。实验结果表明,以1,3-丙磺酸吡啶内盐(PSPy)为相转移催化剂催化甲苯氯甲基化反应的活性最好;甲苯氯甲基化反应的优化条件为:反应温度80℃,反应时间10h、PSPy用量(占甲苯的摩尔分数)8%,n(盐酸)∶n(甲苯)=2;在此条件下,甲苯转化率可达85.7%,单氯甲基化产物(包括对甲基苄氯和邻甲基苄氯)的选择性为96.5%,且PSPy催化剂的重复使用性能较好。

Chloromethylation of Toluene Catalyzed by Amidocyanogen Alkyl Sulfonic Ylide

Seven kinds of amidocyanogen alkyl sulfonic ylides were synthesized and chloromethylation of toluene with hydrochloric acid and paraformaldehyde were studied in the presence of the phase transfer catalysts—amidocyanogen alkyl sulfonic ylides. The effects of the catalyst type and dosage,reaction temperature and time,and hydrochloric acid dosage on the chloromethylation were investigated. The quantitative and qualitative analyses of the products were carried out by means of GC and GC-MS. The results indicated that the catalytic activity of N-propane sulfone pyridinium(PSPy) was the best for the chloromethylation among the synthesized catalysts. Under the optimized reaction conditions of PSPy mole ratio 8%(based on toluene),n(hydrochloric acid):n(toluene)=2,reaction temperature 80 ℃ and reaction time 10 h,the conversion of toluene could reach 85.7%,and the selectivity to monochloromethylation product(1-chloromethyl-4-methyl benzene and 1-chloromethyl-2-methyl benzene)could reach 96.5%. PSPy could be reused without obvious loss of its catalytic activity.