GB321585A - Improvements in the manufacture and production of vat dyestuffs - Google Patents

Abstract

321,585. Johnson, J. Y., (I. G. Farbenindustrie Akt.-Ges.). Dec. 15, 1928. Pyrazolanthrone dyes.-New vat dyes are obtained by treating pyrazolanthrones with free 2- positions with 1-amino-2-halogenanthraquinones or their substitution-products or pyrazolanthrones which are halogenated in the 2-position with 1- aminoanthraquinones with free 2-positions in the presence of alkaline condensing agents, preferably in an organic diluting medium, and in presence of catalysts such as copper, its salts, oxides or mixtures thereof. They are of the following probable, structure :- Halogen derivatives are obtained by the action of a halogenating agent on the condensation products, preferably in an organic or inorganic dissolving medium, such as nitrobenzene, sulphuric acid, oleum, chlorsulphonic acid and the like. The halogenation generally produces an improvement in the clearness of the shade, and in the fastness to chlorine, and also a change in shade. In examples :-(1) pyrazolanthrone is condensed with 1-amino-2-bromanthraquinone; the product dyes cotton blue-violet shades; (2) pyrazolanthrone is condensed with 1 - amino - 2 - brom - 4 - hydroxyanthraquinone, to give a product dyeing bluegreen changing to grey by chlorination; (3) 2- brompyrazolanthrone is condensed with 1-aminoanthraquinone to give a dyestuff similar to that of example (1); (4) 2-brompyrazolanthrone is condensed with 1-amino-4-hydroxyanthraquinone to give a dyestuff similar to that of example (2) ; (5) 2-brompyrazolanthrone is condensed with 1 : 4- diaminoanthraquinone to give a product dyeing greenish-grey, fast to washing, and changing to Bordeaux red by treatment with chlorine; by employing 1-amino-5-benzoylaminoanthraquinone instead of the above 1: 4- -diamino-cornpound, a product dyeing greenish-grey shades is obtained; (6) the dyestuff from example (1) on bromination gives a product dyeing cotton violet shades, changing in air to a blue of good fastness to chlorine; (7) on chlorination of the dyestuff of example (1), a product is obtained dyeing cotton reddish-blue of good fastness to chlorine; (8) bromination of the dyestuff of example (4) gives a product dyeing similarly to the initial dyestuff, but having a purer tone and better fastness to washing.