GB398516A - The manufacture of new azo dyestuffs and intermediate products - Google Patents

Abstract

Azo dyes insoluble in water are made in substance, on a substratum or on the fibre by coupling a 2-hydroxy-5 : 6- or 7 : 8-benzocarbazole - 3 - carboxylic acid-arylamide with a diazo compound. In examples, cotton is impregnated with the p-chloranilide of the 5 : 6- derivative or the p-anisidide of the 7 : 8-derivative and developed with diazotized 4-chloro-2-toluidine or o-chloraniline respectively giving yellowish-brown shades. A table is given showing the shades obtained by using the following additional components: the m-chloranilide, o-toluidide and a -naphthylamide of the 5 : 6-derivative and the o-methyl-p-anisidide, 2-carbazoleamide, b -naphthylamide and 5- or 4-chlor-2-methyl-l-phenylamide of the 7 : 8- derivative; diazo components: m-chloraniline, 5 - or 4 - nitro - 2 - anisidine, b -naphthylamine, 5-chlor-2-toluidine, 2 : 5-dichloraniline, m-aminoazotoluene, 2-chloro-4-benzoylamino-5-methoxyaniline, 4-chlor-2-anisidine, and 4-nitro-2-toluidine. 2 - Hydroxy - 5 : 6 - or 7 : 8 - benzocarbazoles are made by taking a 5 : 6- or 7 : 8-benzocarbazole substituted in the 2-position by a substituent which can be transformed into an OH group and replacing the said substituent by known methods. In examples, (1) 5 : 6-benzocarbazole - 2 - sodium sulphonate (from 2 : 3-oxynaphthoic acid, 3-sulphophenylhydrazine and sodium bisulphite) is fused with potassium hydroxide;, (2) 2-methoxy-7 : 8-benzocarbazole (from a -naphthol, 3-methoxyphenyhydrazine and sodium bisulphite) is heated with aluminium chloride in toluene; Sandmeyers reaction may also be used. 2-Hydroxy-5 : 6- or 7 : 8-benzocarbazole-3-carboxylic acids are made by causing carbon dioxide to act on an alkali metal salt of the corresponding hydroxy compound or upon the hydroxy compound itself in the presence of an alkali metal carbonante. Examples are given. Arylides of 2-hydroxy-5 : 6- or 7 : 8-benzocarbazole-3-carboxylic acids are prepared according to customary methods. In examples, (1) 2-oxy-5 : 6-benzocarbazole-3-carboxylic acid is condensed with p-chloraniline or a -naphthylamine in presence of toluene and phosphorus trichloride, (2) the 7 : 8-derivative is similarly condensed with 5-chlor-2-toluidine in chlorbenzene. Other arylides are also tabulated.