GB561754A - Anthraquinone dyestuffs - Google Patents

Abstract

Vat dyes giving, especially on cotton, dyeings and prints of orange to red shades of the general formula <FORM:0561754/IV/1> wherein one X represents benzoylamino or substituted benzoylamino and the other two X's each represent H, are obtained by condensing 5 - amino - 2 : 1(S) - anthraquinone - thiox - anthone with a 1-chloroanthraquinone substituted in 4, 5 or 8-position by benzoylamino or substituted benzoylamino and ring-closing the resulting anthrimide by treatment with aluminium chloride in nitrobenzene or pyridine. The product is preferably subjected to further treatment with an oxidising agent, e.g. sodium dichromate. In examples: (1) 5-amino-2 : 1 (S)-anthraquinone-thioxanthone is heated for 2 hours at 200 DEG C. with 1-chloro-4-benzoylamino-anthraquinone in nitrobenzene containing soda ash and cupric carbonate and the resulting anthrimide is heated for 1 hour at 50 DEG C. with aluminium chloride in nitrobenzene; the product, pasted with sulphuric acid, gives fast strong red vat dyeings on cotton; (2) the 1-chloro-4-benzoylamino-anthraquinone in (1) is replaced by the corresponding 5-benzoyl-amino compound with heating for 3 hours to form the anthrimide which is further treated as in (1) to obtain a product giving strong orange vat dyeings on cotton.