ECO-FRIENDLY METHOD FOR CATALYTIC AERIAL OXIDATION OF ALOE-EMODIN TO RHEINAL

摘要

A process for preparation of 4,5-Dihydroxy-9,10-dioxo-9,10-dihydro-anthracene-2-carbaldehyde from 1,8-Dihydroxy-3-hydroxymethyl-anthraquinone comprising of aerial oxydation of 1,8-Dihydroxy-3-hydroxymethyl-anthraquinone at oxygen pressure of about 1 to 2 bar in presence of a transition metal complex, a co-catalyst and optionally an oxidizing agent in an organic solvent such as 1,4 dioxane, water or mixtures thereof at a temperature ranging between 25 to 100°C, isolation by appropriate process and optional purification of the product.