摘要 |
<p>In the preparation of 2,3,5-trimethyl-hydroquinone diesters (I) by catalytic acylation of keto-isophorone (II), the acylating agent is a carboxylic anhydride containing a 1-4C alkyl residue, the reaction solution is cooled to -10 to 35 (preferably 0-30) degrees C, the crystallized (I) is filtered off and the filtrate is recycled to the acylation. In the preparation of 2,3,5-trimethyl-hydroquinone diesters (I) by catalytic acylation of keto-isophorone (II), the acylating agent is a carboxylic anhydride containing a 1-4C alkyl residue, the reaction solution is cooled to -10 to 35 (preferably 0-30) degrees C (optionally after distilling off part of the obtained carboxylic acid (III)), the crystallized (I) is filtered off and the filtrate is recycled to the acylation (optionally after distilling off part of (III) and/or discarding part of the filtrate).</p> |