GB303123A - Manufacture of vat-dyestuffs - Google Patents

Abstract

303,123. I. G. Farbenindustrie Akt.- Ges. Dec. 28, 1927, [Convention date]. Isoviolanthrone dyes.-Vat dyes of the isoviolanthrone series are obtained by treating 1 : 4- dihalogen-8-aroylnaphthalenes or their substitution products with alkaline condensing agents, in the presence or absence of diluents. The parent halogenaroylnaphthalenes may be obtained in the manner described in Specification 301,311. According to examples, (1) 1 : 4-dichlor-8-benzoylnaphthalene is heated with alcoholic potash; the product appears to be identical with isoviolanthrone, (2) 1 : 4 - dichlor - 8 - p - - chlorbenzoylnaphthalene when similarly treated yields a product which dyes cotton from a blue vat in violet tints of a more reddish blue than isoviolanthrone, (3) 1 : 4 - dichlor-7-o-chlorbenzoylnaphthalene is heated with caustic potash and quinoline; the product dyes cotton in somewhat more bluish tints than isoviolanthrone, (4) 1:4-dichlor-8-alphanaphthoylnaphthalene is heated with caustic potash and aniline; the product, probably 5 : 6 : 5<1> : 6<1>-dibenzisoviolanthrone, dyes in reddish-blue tints, (5) 1 : 4-dichlor-8-#-naphthoylnaphthalene is heated with alcoholic potash; the product dyes cotton a pure blue tint, (6) 1 :4-dichlor-8-ptoluylnaphthalene is heated with alcoholic potash; the product, probably 7 : 7<1>-dimethylisoviolanthrone, dyes cotton a very reddish violet tint : the corresponding o- and m-toluyl compounds yield products dyeing in more bluish shades. The Specification as open to inspection under Sect. 91 (3) (a) comprises also the production of vat dyestuffs from the ketones obtained by condensing 1 : 4-dichlornaphthalene with anthraquinone-#-carboxylic acid chlorides. This subjectmatter does not appear in the Specification as accepted.