Patent GB-569080-A (GB)
Title: Manufacture of new dyestuffs and intermediates therefor
IPC: C09B35/08
Filed: 1943-06-23
Abstract: 2 : 21-Dichloro-3 : 31-dimethylbenzidine-5 : 51-disulphonic acid is obtained by sulphonating 2 : 21 - dichloro - 3 : 31 - dimethylbenzidine, e.g. with a mixture of 100 per cent sulphuric acid, anhydrous sodium sulphate and 65 per cent oleum.  Disazo dyes are obtained by tetrazotising the above diamine and coupling with 2 mols. of the same or different coupling components.  Phenolic groups may subsequently be ethylated or acylated with an aryl sulphonyl halide.  The products give on wool level dyeings, fast to light and to wet treatments and, when no more than two sulphonic acid groups are present, give similar dyeings on nylon.  Specified coupling components are 1 - phenyl - 3 - methyl - 5 - pyrazolone, its 31- or 41-nitro, 31- or 41-amino, 31- or 41-sulpho, 41 : 31- or 21 : 51-chloro-sulpho and 21 : 51 - dichloro - 41 - sulpho derivatives 1 - (31 : 41 - dichloro)phenyl - 5 - pyrazolone 1-phenyl-5-pyrazolone-3-carboxylic acid and its 41-nitro derivative, 1-phenyl-5-pyrazolone-3-carboxylic acid ethyl ester and its 41-nitro derivative, 1-(41 : 81-disulpho-21-naphthyl)-3-methyl - 5 - pyrazolone, 1 - (41 : 81 - disulpho - 21-naphthyl)-5-pyrazolone-3-carboxylic acid, the anilide, o- and p-chloroanilides, o-toluidide, m-xylidide and p-phenetidide of acetoacetic acid, naphthionic acid, 1- and 2-acetylamino-7-naphthols, 2 : 3-hydroxynaphthoic acid and its anilide, 2 : 3-aminonaphthoic acid, the N-acetyl, N-carbethoxy, N-b -aminoethyl, N-phenyl, N-benzoyl, N-(41-nitro)benzoyl and N-p-toluenesulphonyl derivatives of 2 : 5 : 7-aminonaphtholsulphonic acid, 2 : 8 : 6-aminonaphtholsulphonic acid and its N-phenyl derivative, the N-acetyl derivatives of 1 : 8 : 4-, 1 : 8 : 6- and 1 : 5 : 7-aminonaphtholsulphonic acids, phenol, with subsequent ethylation of the phenolic hydroxy group with ethyl p-toluenesulphonate, p-cresol, 1 : 3 : 5-xylenol, resorcinol, o-cyclohexylphenol, 4-hydroxydiphenyl, 2-chloro-4-tert.-butylphenol, salicylic, o- and p-cresotinic and a -resorcylic acids, 4-methylphenol-2-sulphonic acid, 5 : 5-dimethyl-5 : 6-dihydroresorcinol, barbituric acid, ethyl acetoacetate, b -naphthol, tetrahydro-b -naphthol, 1-naphthol-4-methyl ketone, 1 : 3-, 1 : 4-, 1 : 5-, 2 : 6- and 2 : 8-naphtholsulphonic acids, naphthionic acid, 1 : 3 : 6- and 2 : 6 : 8-naphtholdisulphonic acid, 8-hydroxyquinoline and its 5-sulphonic acid, citrazinic acid, 2 : 4-dihydroxy-5 : 6-dihydropyrindene and 2 : 4 - dihydroxyquinoline. Examples are given of the coupling with (a) 1-phenyl-3-methyl-5-pyrazolone (2 mols.), (b) 1-phenyl-3-methyl-5-pyrazolone (1 mol.) and 2 : 4-dihydroxyquinoline (1 mol.), (c) 1-(41-sulphophenyl)-3-methyl-5-pyrazolone (1 mol.) and phenol (1 mol.), with subsequent acylation with p-toluenesulphonyl chloride, benzenesulphonyl chloride, p-chlorobenzenesulphonyl chloride or b -naphthalenesulphonyl chloride.  1 - (41 - Chloro - 31 - sulpho)phenyl - 3 - methyl - 5-pyrazolone is obtained by condensing with ethyl acetoacetate the hydrazine obtained by reducing diazotised 4-chloroaniline-3-sulphonic acid with sodium bisulphite.  1 - (31 : 41 - Dichloro)phenyl - 5 - pyrazolone is obtained by condensing with ethyl formoacetate the hydrazine obtained by reducing diazotised 3 : 4-dichloroaniline with sodium bisulphite.  1-(41 : 81-Disulpho-21-)naphthyl - 3 - methyl - 5-pyrazolone and 1-(41 : 81-disulpho-21-)naphthyl-5-pyrazolone-3-carboxylic acid are obtained by condensing with ethyl acetoacetate and ethyl oxaloacetate respectively the hydrazine obtained by reducing diazotised 2 : 4 : 8-aminonaphthalenedisulphonic acid with stannous chloride and, in the latter case, hydrolysing the carboxylic ester group in the product with caustic soda.  2 - (b  - aminoethyl)amino - 5 - naphthol - 7 - sulphonic acid is obtained by reaction of ethylene diamine with the 2 : 5 : 7-acid in presence of sodium bisulphite.  N - Acetyl - 1 : 8 : 6 - aminonaphtholsulphonic acid is obtained by reaction of acetic anhydride with the 1 : 8 : 6-acid.  2 : 4 - Dihydroxy - 5 : 6 - dihydropyrindene is obtained by hydrolysing the diazotised corresponding 2-amino compound obtained by treating N-acetylated 2-cyanocyclopentylideneimine with sodamide in liquid ammonia.