| 摘要 |
<p>A continuous process for the preparation of thymol by propylation of m-cresol with propylene and/or compounds which eliminate propylene, characterized in that the reaction is carried out over aluminium oxide catalysts in the presence of a nitrogen base. This process is distinguished by the fact that it yields, even in the presence of small amounts of water in the mcresol, and independently of the starting material, that is to say independently of whether m-cresol and propylene, or by-products arising in working up crude thymol, are employed, a crude thymol of constant composition and quality from which thymol in a purity of over 99.5% can be isolated without difficulties, and the by-products of which can always be recycled to the reaction. In the process according to the invention, the activity of the catalyst also remains preserved for very long periods.</p> |
