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Highly Selective Vapor‐Phase Acylation of Veratrole over H 3 PO 4 /TiO 2 ‐ZrO 2 : Using Ethyl Acetate as a Green and Efficient Acylating Agent
Author(s) -
Javad Kalbasi Roozbeh,
Abbaspourrad Alireza,
Massah Ahmad Reza,
Zamani Farzad
Publication year - 2010
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.201090066
Subject(s) - chemistry , acylation , reagent , catalysis , ethyl acetate , alkylation , organic chemistry
A simple sol‐gel method with and without surfactant was applied to prepare TiO 2 ‐ZrO 2 mixed oxides containing Ti and Zr at a molar ratio of 1:1. Several catalysts containing w =15% –35% H 3 PO 4 were set up using these mixed oxides. The physical and chemical properties of catalysts were investigated by BET, SEM and pyridine adsorption‐desorption. The catalytic performance of each material was determined for the vapor‐phase acylation of veratrole (1,2‐dimethoxybenzene) to 3,4‐dimethoxyacetophenone (3,4‐DMAP), which was found to be the major product of the reaction of veratrole with ethyl acetate, with alkylated products being the minor products. 2,3‐Dimethoxyacetophenone (2,3‐DMAP) was not detected in the product stream. In the best experimental conditions, the alkylated products were less than 0.7%. This reaction may represent an environmentally friendly alternative to use the ethyl acetate as the acylating reagent. The feed molar ratios of veratrole/ethyl acetate were varied over a wide range of 0.1 to 1, and the optimum feed ratio of veratrole/ethyl acetate was 1:3. Space velocity employed in the veratrole acylation reported as WHSV (veratrole) was 1.2 h −1 . The acylation reactions were carried out in the temperature range of 423 to 673 K and the optimum H 3 PO 4 content for acylation was w =15%.