N,N'-Diphenyldiimides of 6,12, dialkyl-3,4,9,10-anthanthrene-tetracarboxylic acid

Abstract

Novel anthanthrene derivatives characterized by the general formula ##STR1## where Alk is an alkyl C.sub.1 -C.sub.10, X.sub.1, X.sub.2 and X.sub.3, X.sub.4 stand for a group (1) --CH.sub.2 --CH.sub.2 -- or a group ##STR2## wherein Y is an oxygen atom or an imino-group, either unsubstitutedor containing substituents: alkyl, cycloalkyl, aryl; or, else, one of X.sub.1 and X.sub.2, as well as one of X.sub.3 and X.sub.4 is a CO-group, the other X then entering, corresponding, into the benzimidazole cycle. The structure of said compounds can be either symmetrical or non-symmetrical with respect to X.sub.1, X.sub.2 and X.sub.3, X.sub.4. Said anthanthrene derivatives are produced by cyclization in the presence of condensing agents of compounds having the formula ##STR3## where Z is either CHOH or CO, and Alk, X.sub.1, X.sub.2, X.sub.3 and X.sub.4 are as defined above. Some of the said anthanthrene derivatives are used as dyes or pigments, while others serve as starting products for producing dyes or pigments.

Dependencies are inferred from the claim text.