GB295645A - Process for the manufacture of vat dyestuffs of the anthraquinone series - Google Patents

Abstract

295,645. Carpmael, W., (I, G. Farbenindustrie Akt.-Ges.). May 14, 1927. Anthraquinoneacridones.-Diphthalylacridones are converted into new vat dyes by treating them with nitrating agents, e.g. concentrated nitric acid or a mixture of nitric and sulphuric acids. The products may be reduced to the amino derivatives; both the nitro and amino compounds dye cotton from the vat, usually in greyish-blue shades. The aminoderivatives can also be acylated, yielding grey vat dyes of particularly good fastness properties. In examples, (1) 3 : 4 : 5 : 6-diphthalylacridone is heated with nitric acid, the nitroacridone separates out on cooling and may be reduced to the aminoacridone by means of aqueous sodium hydrosulphite solution, advantageously in the presence of alcohol; on treating the amino compound with benzoyl chloride, in nitrobenzene solution a dyestuff is obtained which dyes cotton from the vat in very fast violet-grey shades, and (2) 1 : 2 : 5 : 6- diphthalylacridone (obtainable by condensing 1- chlorawthraquinone-2-carboyic acid with 2- aminoanthraquinone and subsequently closing the ring by means of sulphuric acid) is nitrated by means of a mixture of nitric, and sulphuric acids and the product is reduced to the, amino' compound by reduction with alkaline hydrosulphite and subsequent blowing out of the vat with air; the benzoyl derivative dyes cotton from the vat, in fast olive-green shades. Specification 894/11 and German Specification 268,219 are referred to.