Highly Selective Vapor-Phase Acylation of Veratrole over H3PO4/TiO2-ZrO2: Using Ethyl Acetate as a Green and Efficient Acylating Agent
✍ Scribed by Roozbeh Javad Kalbasi; Alireza Abbaspourrad; Ahmad Reza Massah; Farzad Zamani
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 360 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0256-7660
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✦ Synopsis
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%.