1-Amino-anthraquinone-2-carboxylic acid cpds. prodn. from 2-methyl cpds. - by oxidn. with nitrobenzene in aq. inorganic base using phase transfer catalyst

摘要

Prodn. of 1-aminoanthraquinone-2-carboxylic acids of formula (I) by oxidn. of 1-amino-2-methylanthraquinones of formula (II); X = H, Cl or Br; with nitrobenzene (III) under alkaline conditions, followed by acidification of the reaction mixt., the novelty is that oxidn. is carried out in an aq. inorganic base (IV) in the presence of a phase transfer catalyst. Pref. (IV) is an aq. soln. or suspension or alkali(ne earth) hydroxide, eps. NaOH. Oxidn. is carried out at 90-140 deg.C. USE/ADVANTAGE - (I) are used in dyestuff synthesis. They are obtd. in good yield and good purity, suitable for direct use for this purpose, by a simple and economical process, which is suitable for continuous or batch operatio