| 摘要 |
1. Process for cyclization of orthobenzoylbenzoic acid in which the anthraquinone formed sublimes, by heating orthobenzoylbenzoic acid in the presence of a super-active bleaching clay consisting of a clay of the bentonite type activated by treatment with an inorganic acid, washed with water so that it only contains 0.1% at most of acid, expressed as hydrochloric acid, and finally dried at a temperature equal at most to 120 degrees C, at a temperature of between 300 degrees C and 400 degrees C, characterized in that orthobenzoylbenzoic acid in the solid state and the super-active bleaching clay are brought into contact in the form of a mixture of solids arranged in a layer of thickness such that the anthraquinone formed and sublimed diffuses completely, or in the form of two superposed layers of solids, the super-active bleaching clay layer covering that of orthobenzoylbenzoic acid so that the anthraquinone formed and sublimed diffuses completely. |
