Cao Pinga,b,c, Yang Xian-gui a,c, Tang Cong-ming a,c, Wang Gong-ying a, c*
(a Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, China) (b Chongqing University of Technology, Chongqing 400054,China) (c Changzhou Key Laboratory of Green Chemistry & Technology, Changzhou Institute of Chemistry, Changzhou 213164, China)
Abstract: Diphenyl carbonate (DPC) is considered as a substitution for phosgene to synthesize polycarbonates (PCs), and some methods are used for the synthesis of DPC, such as the transesterification of dimethyl carbonate (DMC) with phenyl acetate (PA), dimethyl carbonate (DMC) with phenol, and dimethyl oxalate(DMO) with phenol. In this prescript, the catalytic performance of some metal acetylacetonates and titanium compounds for transesterification of DMC with PA to DPC was measured and it was found that bis(acetyl acetonate) titanium oxide (TiO(acac)2) was a novel and efficient catalyst and it is testified that Ti was the catalytic center of the catalyst. When the reaction was carried out at 180 ºC, with a molar ratio of PA to DMC of 2:1, a reaction time 4 h, a catalyst amount 0.6% (molar ratio to PA), the conversion of DMC was 74.9%, and the selectivity of DPC and MPC was 38.9% and 56.9%, respectively. Furthermore, a plausible mechanism for the transesterification of DMC and PA to MPC and DPC catalyzed by TiO(acac)2 was proposed by changing the feeding order of the materials and catalyst.
Key words: bis(acetyl acetonate) titanium oxide; dimethyl carbonate; phenyl acetate; transesterification; diphenyl carbonate; mechanism
E-mail: gywang@cioc.ac.cn
Journal of Molecular Catalysis, Vol. 24, Issue 6, 2010, 492~498.
