GB424453A - Manufacture of new monoazo dyestuffs - Google Patents

Abstract

Chromable green dyes are obtained by coupling a 1-arylamino-8-naphthol-4-sulphonic acid, which may contain another sulphonic acid group or groups and in which the aryl nucleus may carry substituents such as alkyl or alkoxy groups, with a diazotized unsulphonated 2-aminophenol substituted in the 6-position with halogen or a nitro, alkyl, alkoxy, acylamino or carboxy group, and possibly substituted in another position with halogen or a nitro, carboxy, sulphonamide, N-dialkylsulphonamide, or N-alkylarylsulphonamide group; the diazo compound must contain at least one halogen atom or nitro group. Specified diazo compounds are those from 4 : 6-dichloro-2-aminophenol, 4 : 6-dinitro-2-aminophenol, 6-nitro-2-aminophenol, 6-chloro-2-aminophenol, 4-chloro-6-nitro-2-aminophenol, 4-bromo-6-nitro-2-aminophenol, 4-nitro-6-chloro-2-aminophenol, 3 : 4 : 6-trichloro-2-aminophenol, 6-methyl-4-nitro-2-aminophenol, 4-nitro-6-methoxy-2-aminophenol, 6-acetylamino-4-chloro-2-aminophenol, 5-chloro-3-amino-2-hydroxybenzoic acid, 5-nitro-3-amino-4-hydroxybenzoic acid, and 6-chloro-2-aminophenol-4-sulphonamide and its N-dialkyl or N-alkyl-aryl substitution products. Specified coupling components are 1-phenylamino-8-naphthol-4-sulphonic acid, 1-p-tolylamino-8-naphthol-4-sulphonic acid, 1-p-methoxyphenylamino-8-naphthol-4-sulphonic acid, and 1-arylamino-8-naphthol-4 : 6-disulphonic acids. Specifications 5749/06, [Class 2], 192,438, [Class 2 (iii)], and 351,400 are referred to. 4-Nitro-6-methoxy-2-aminophenol is prepared by treating 2 : 4-dinitro-6-chlorophenol with methanol and caustic soda, and reducing the product with sodium sulphide. 6-Acetylamino-4-chloro-2-aminophenol is prepared by acetylating 6-amino-4-chloro-2-nitrophenol and reducing the product. 5-Chloro-3-amino-2-hydroxybenzoic acid is prepared by nitrating 5-chloro-2-hydroxybenzoic acid and reducing the product. 5-Nitro-3-amino-4-hydroxybenzoic acid is prepared by dinitrating 4-hydroxybenzoic acid and reducing the product wirh sodium sulphide. The Specification as open to inspection under Sect. 91 states that carboxylic acid esters of 5-chloro-3-amino-2-hydroxybenzoic acid and of 5-nitro-3-amino-4-hydroxybenzoic acid may be used as diazo components. The statement of claim indicates that the diazo component may be a halogenated (or nitrated) unsulphonated 2-aminophenol substituted (a) in the 6-position with a sulphonamide, N-dialkyl-sulphonamide, or N-aryl-alkylsulphonamide group or with a carboxylic amide group or N-dialkyl derivative thereof, and (b) in another position with an alkyl, alkoxy or acylamino group or with a carboxylic amide group or N-dialkyl derivative thereof. The statement of claim states also that the aryl group in the coupling component may be substituted by halogen or by a nitro or substituted amino group. This subject-matter does not appear in the Specification as accepted.