GB513281A - Manufacture of a vat dyestuff - Google Patents

Abstract

513,281. Dyes. DU PONT DE NEMOURS & CO., E. I. April 5, 1938, No. 10471. Convention date, April 5, 1937. [Class 2 (iii)] An anthragninone vat dyestuff of the formula is manufactured by interacting one molecular proportion. of 1:5-diaminoanthraquinone with two of 1-chloro-5-benzoylaminoanthraquinone, or one of 1:5-dichloroanthraquinone with two of 1-amino-5-benzoylaminoanthraquinone, and converting the resulting dibenzoylaminotrianthrimide to the carbazole by treating it with anhydrous aluminium chloride, e.g., in the presence of nitrobenzene, and then with an oxidizing agent, e.g., a bichromate in dilute sulphuric acid, or an alkaline hypochlorite solution. The interaction of the starting materials may be effected by heating them together in an inert organic solvent, e.g., nitrobenzene (in which case the aluminium chloride treatment may be effected without isolation of the anthrimide), pyridine or trichlorobenzene, in the presence of a copper salt, e.g., cuprous or cuproic chloride, as catalyst, and of an acidbinding agent, e.g., sodium carbonate or sodium acetate. The product dyes and prints cotton and other cellulosic textile materials, orange shades. Specifications 461,432 and 497,971 are referred to.