GB274211A - Process for the manufacture of new anthraquinone derivatives - Google Patents

Abstract

274,211. Carpmael, W., (I. G. Faybenindustrie Akt.-Ges.). April 19, 1926. p-Diaminoanthrarufin derivatives. - p-Diaminoanthrarufin-2 : 6-disulphonic acid or an N- methyl derivative thereof is treated, in the form of its boric acid ester in sulphuric acid solution, with an aromatic oxy compound or an ether thereof, in equimolecular quantity or excess. Addition products are first obtained, that from phenol being probably Upon treatment with acid or alkaline agents these compounds are transformed into others in which the phenol residue has probably replaced a sulpho group, the latter being eliminated as sulphurous acid. The compound from phenol is probably These compounds dye wool or mordanted wool in fast blue shades. By removing the second sulpho group by known methods there may be obtained further products also applicable as mordant dyestuffs or as starting materials for other compounds. According to examples, (1) pdiaminoanthrarufin-2 : 6-disulphonic acid is heated with sulphuric and boric acids until formation of the boric ester is complete, cooled to 10‹ C. and phenol added; the initial brownyellow addition product is isolated by dilution with glacial acetic acid and dyes wool in yellow shades changed to blue by prolonged boiling : (2) p - di-(methylamino)-anthrarufin-2 : 6-disulphonic acid (Specification 250,968) is similarly treated with anisole and the initial addition product isolated as the calcium salt : (3) the addition product of example 1 is 'dissolved in water and treated with caustic soda in the cold or with ammonia, sodium carbonate, or dilute mineral acids at higher temperature; the product dyes wool in blue shades and yields a salt with pyridine; (4) the reaction mixture from pdiaminoanthrarufin-2 : 6-disulphonic acid, boric acid, and anisole is diluted' and the yellow solution heated either as such or after rendering alkaline; a blue dyestuff separates, which also yields a pyridine salt; (5) the pyridine salt of example 3 is stirred with ammonia and hydrosulphite, an orange coloured hydro-compound being produced; on heating, the sulpho group is eliminated; the unsulphonated product separating may be crystallized from pyridine or nitrobenzene; it dyes chrome mordanted wool in blue shades. The phenol or anisole may be replaced by resorcin, pyrocatechin, hydroquinone, phenetole, naphthols, guaiacol, verabrol, diphenylether, or chlorphenols. The splitting off of the second sulpho group may also be effected by heating with dilute acids under pressure.