有机钛催化草酸二甲酯与苯酚酯交换反应

Organotitanium Compound Catalysts for Transesterification of Dimethyl Oxalate with Phenol

研究了几种有机钛化合物对草酸二甲酯(DMO)与苯酚酯交换反应的催化性能,发现催化活性及选择性顺序依次为二氯二茂钛>钛酸四苯酯>钛酸丁酯>乙酰丙酮氧钛>钛酸乙酯>钛酸异丙酯,表明二氯二茂钛是一种性能较好的酯交换催化剂.在n(Cp2TiCl2)=0.001 mol、n(DMO)=0.3 mol、n(Phenol)=0.2 mol、T=180℃、t=2 h优化工艺条件下,苯酚转化率可达44.0%,甲基苯基草酸酯(MPO)和草酸二苯酯(DPO)收率分别达37.8%和6.1%,酯交换总选择性为99.8%.

The catalytic performance of several organotitanium compounds for transesterfication of dimethyl oxalate with phenol was investigated. The results showed that the catalytic activities and selectivities were in the order： CpzTiC12〉Ti（ OPh）a〉Ti（ OBu）4〉TiO（acac）2〉Ti（ OEt）4〉Ti（ OEt）4. This means that Cp2TiCI： was an efficient transesterfication catalyst compared to the others. Under the optimal conditions （ n （ Cp2TiCl2 ） = 0. 001 mol, n （DMO）= 0.3 mol, n（Phenol） = 0.2 tool, T= 180 ℃, t= 2 h ）, the conversion of phenol reached 44.0% , and the yield of MPO and DPO were 37.8% and 6.1% , respectively, while the total transesterfication selectivity was 99.8%.