| 摘要 |
<p>A process, which does not pollute the environment, for the preparation of quinizarin consists in reacting a mixture of phthalic anhydride p-chlorophenol, sulphuric acid and boric acid or boric anhydride at elevated temperatures in such a way that, in the reaction mixture, there is sulphuric acid preferably containing 10-20% of free SO3 and the weight ratio of p-chlorophenol to the total amount of H2SO4+SO3 is 1:1.5 to 4.0. Yields and purity of the product are outstanding, despite the concentrated procedure.</p> |
