GB210669A - Manufacture of dyestuffs derived from pyrazolone and of intermediate products therefor - Google Patents

Abstract

1- (Sulphonamido-aryl) -5-pyrazolones are prepared by converting amides of sulphonic acids of primary aromatic amines into the corresponding hydrazines and condensing the latter with the appropriate derivatives of b -ketonic acids, such as ethyl acetoacetate or oxaloacetate. According to examples 1- (31-sulphonamidophenyl) - 3 - methyl-5-pyrazolone is obtained by reducing with sulphite the diazo compound of 3-aminobenzene-1-sulphonamide and condensing the hydrazine with ethyl acetoacetate; 1- (31-sulphonamido-61-methylphenyl) -5-pyrazolone-3-carboxylic acid is similarly obtained from 3-amino-4-methylbenzene-1-sulphonamide and ethyl oxaloacetate: the pyrazolones from 3-aminobenzene-1-sulphonamide, 3-amino-4-methylbenzene-1-sulphonamide, 3-amino-4-chlorbenzene-1-sulphonamide, or 4-aminobenzene-1-sulphonamide and ethylacetoacetate or oxaloacetate, are also described. 4-Chlor-3-aminobenzene-1-sulphonamide is prepared by nitrating p-chlorbenzenesulphonic chloride, treating with ammonia, and reducing the nitro group with iron and acetic acid. Monoazo dyes; chromium compounds of azo dyes; lakes.-Azo dyes are obtained by coupling the above described sulphonamidoaryl-pyrazolones with diazo compounds; some of the products dye wool in yellow to red or brown shades which may be afterchromed; those derived from o-diazophenols and o-diazonaphthols are mordant dyestuffs and may also be converted into chromium compounds by treating with chromium salts, or with chroming agents in alkaline or neutral solution as described in Specifications 104,045, 116,535, 186,635, and 191,972: the dyestuffs are also applicable in the manufacture of lakes. Products from the following pairs of components are described in examples:- o-aniline sulphonic acid or 4-toluidine-3-sulphonic acid and 1- (31-sulphonamidophenyl) -5-pyrazolone-3-carboxylic acid; 2-naphthylamine-1-sulphonic acid or sulphanilic acid and 1- (31-sulphonamido-61-methylphenyl) -3-methyl-5-pyrazolone; 2-amino-phenol-4-sulphonic acid, or 1-amino-2-oxynaphthalene-4-sulphonic acid, or nitro-1-diazo-2-oxynaphthalene-4-sulphonic acid, and 1- (31-sulphonamidophenyl) -3-methyl-5-pyrazolone or the corresponding 3-carboxylic acid. Chromium compounds of the dyestuffs from 1-amino-2-oxynaphthalene-4-sulphonic acid (or its nitrated derivative), or 4-chlor-2-aminophenol-5-sulphonic acid, and 1- (31-sulphonamidophenyl) -3-methyl-5-pyrazolone are made, according to further examples, by boiling the dyestuffs with chromium fluoride, acetate, formate, or oxide, and of the dyestuff from 1-amino-2-oxynaphthalene-4-sulphonic acid and 1- (31-sulphonamido-phenyl) -3-methyl-5-pyrazolone by heating with a solution made by boiling chromium oxide with glycerine and caustic potash solution.