GB244462A - The manufacture of new anthraquinone derivatives - Google Patents

Abstract

The condensation of formaldehyde or a substance which yields it with 4-substituted-1-aminoanthraquinones or their derivatives in the presence of an acid condensing agent is carried out to a stage such that the products are not decomposed into their components by the the action of water or dilute acids; the same products may be obtained by further condensing, for example by the action of sulphuric acid, the known compounds from 4-substituted-1-aminoanthraquinones and formaldehyde in which the latter is only loosely combined. Two series of compounds can be obtained, namely, Series I by using 1 mol. formaldehyde to 1 mol. anthraquinone derivative, and Series II by using 2 or more mols. formaldehyde to 1 mol. anthraquinone derivative: the compounds of Series II upon treatment with oxidizing agents such as manganese dioxide in sulphuric acid or even with the acid itself are converted into others from which 1 mol. formaldehyde can be readily split off leaving compounds of Series I. The parent Q 1-aminoanthraquinone derivatives may be alkylated or aralkylated in one or more amino groups. As condensing agents may be employed aqueous sulphuric acid, mixtures of glacial acetic and hydrochloric, sulphuric, or phosphoric acids, phosphoric acid, phosphorus oxychloride, aluminium chloride and the like; when sulphuric acid alone is employed it must be of 65-85 per cent strength. The production of the following compounds is described in examples:-(1) compounds of Series I or II and mixtures thereof from 1 : 4-amino-oxyanthraquinone and paraformaldehyde in presence of diluted sulphuric acid, a mixture of acetic acid and sulphuric or phosphoric acid, or sulphuric acid and boric acid; (2) a compound of Series II by action of phosphorus oxychloride on 1 : 4-amino-oxyanthraquinone suspended in formaldehyde solution; (3) compounds of Series I or II from 1 : 4-diaminoanthraquinone or 1 : 4-methoxyaminoanthraquinone and trioxymethylene or paraformaldehyde in sulphuric acid; (4) compounds or Series I by oxidizing the compounds of Series II obtained from 1 : 4-amino-oxyanthraquinone with sulphuric acid, or manganese dioxide and sulphuric acid, and eliminating formaldehyde by washing with water. In place of formaldehyde, paraformaldehyde, or trioxymethylene may be used methylene diacetate, methylal, or formaldehyde-bisulphite. The compounds obtained from 1 : 4-amino-oxyanthraquinone or 1 : 4-aminomethoxyanthraquinone dye cotton from a violet hydrosulphite vat in bluish grey to black shades. Specifications 22128/01 and 4648/11 are referred to. The Specification as open to inspection under Sect. 91 (3) (a) refers to the condensation with formaldehyde, or substances which yield it, of 1-aminoanthraquinone and its derivatives in general. This subject-matter does not appear in the Specification as accepted.