Synthesis, characterization of triphenyltin grafted on SBA-15 mesoporous silica and its catalytic performance for the synthesis of 4-methylacetophenone

The production of Ph3Sn-O-SBA-15 (Ph(3)SnSBA) was achieved by heating triphenyltin chloride and SBA-15 in N-methylpyrrolidone at 190 degrees C for 5 h using triethylamine as a catalyst. The composition, structure, and surface physical and chemical properties of Ph(3)SnSBA were characterized using inductively coupled plasma-atomic emission spectroscopy (ICP-AES), C-13, Sn-119 and Si-29 solid-state nuclear magnetic resonance (NMR) spectroscopy in situ pyridine infrared spectroscopy (Py-IR), N-2 adsorption-desorption isotherms, X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results of ICP-AES and organic elemental analysis showed that the grafting yield of Sn was 17% (by mass) for Ph(3)SnSBA. The elemental analysis and solid-state NMR results for Ph(3)SnSBA were consistent with grafting of triphenyltin on SBA-15. The N-2 adsorption-desorption, XRD and TEM analyses showed that Ph(3)SnSBA retained an ordered hexagonal mesoporous structure, resulting in decreases in the surface area, pore size and mesopore volume, and an increase in acidity as compared with SBA-15. The Hammett acidity function (H-0) value and the number of acid sites for Ph(3)SnSBA, obtained by the Hammett methods, were 2.77-3.30 and 2.07 mmol.g(-1), respectively. The Friedel-Crafts acylation of toluene and acetic anhydride over Ph(3)SnSBA was investigated. The yield of methylacetophenone (MAP) and the selectivity for 4-methylacetophenone (PMAP) were 79.56% and 97.12%, respectively, when the conditions were n (toluene): n (anhydride) = 2.0: 1.0 with 6% (by mass) catalyst, and heating under reflux for 5 h. The PMAP selectivity still reached 93.11% when Ph(3)SnSBA was used for the fifth time under the same reaction conditions. (C) 2014 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.