Process for the preparation of N,N' -disubstituted 1,4-diaminoanthraquinones
OwnerUlrich Feldhues, Josef-Walter Stawitz +1inventors
InventorsUlrich Feldhues, Josef-Walter Stawitz, Julius Naseband
Life of this patent
Estimating the term…
Abstract
Process for the preparation of N,N′-disubstituted 1,4-diaminoanthraquinones 1 in which R is an aliphatic or aromatic radical, characterized in that 1,4-dihydroxyanthraquinones are reacted with aliphatic or aromatic amines in the presence of a readily water-soluble, dipolar-aprotic solvent (e.g. NMP) and of a second solvent, different from the first.
Claims19
Process for the preparation of N,N′-disubstituted 1,4-diamino-anthraquinones, comprising reacting 1,4-dihydroxyanthraquinones with aliphatic or aromatic amines in the presence of a dipolar-aprotic solvent possessing a solubility in water of at least 30% by weight at 20° C., and at least one second solvent, different from the first.
Dependencies are inferred from the claim text.