PROCESS FOR PRODUCING RHEIN AND DIACERHEIN

摘要

The following description sets forth a process for producing rhein, diacerhein and other diacyl derivatives thereof, which comprises the following steps: treatment of a diphenylketone (See Fig. I) in which R1 is -OR', -NR'R", -SR', where R' and R" are H, an alkyl or aromatic group; R2 is H or a protective group, R3 is -OH or C1-C4 alkyl, with an acid or superacid to give a 1-aminoanthraquinone derivative, diazotisation, replacement of the -NH2 group by -OH, optional removal of the protective group, and acylation.