GB399241A - Manufacture of vat-dyestuffs - Google Patents

Abstract

Vat dyes of the general formula:-- <FORM:0399241/IV/1> wherein R1 and R2 represent residues capable of being vatted, of which at least one is different from 1- or 2-anthraquinonyl, are prepared by condensing two molecular proportions of a 1,3-dihalogenanthraquinone with one molecular proportion of a diaminoanthraquinone, causing the product to react with two molecular proportions of an anthraquinone derivative containing an amino group and treating the product with an acid condensing agent. The presence of a high-boiling solvent and a catalyst in the reaction is advantageous. In examples (1) 2 mols. of 1,3-dibromanthraquinone are condensed with 1 mol. of 1,4-diaminoanthraquinone and the product reacted with 2 mols. of 1-aminoanthraquinone and condensed by means of aluminium chloride in pyridine to give a blackish-olive dye; replacing 1,4-diaminoanthraquinone by 1,5-diaminoanthraquinone gives a reddish-brown dye; replacing the 1-aminoanthraquinone by 1,4-monobenzoyl-diaminoanthraquinone gives an olive dye. A further example illustrates the application of the first dye to cotton. It is stated that the diaminoanthraquinone reacts with the a -halogen atom of the 1,3-dihalogenanthraquinones. The Provisional Specification relates to the production of dyes by condensing either a 1,3-dihalogenanthraquinone or a 1,3-diaminoanthraquinone with a diaminoanthraquinone or a dihalogenanthraquinone respectively and thereupon causing the product to react with an anthraquinone derivative containing an amino group or a halogen atom respectively, and finally treating the product with an acid condensing agent.