GB475938A - Manufacture of new azo dyestuffs - Google Patents

Abstract

Azo dyes are made by tetrazotizing 1 molecular part of a diamine of the formula <FORM:0475938/IV/1> or a diamine of the formula <FORM:0475938/IV/2> where R1 and R3 may be substituted and R2 = an alkyl radical of at least 10 C atoms, and coupling with 2 molecular parts of the same or two different coupling components. Some of the dyestuffs may also be made by way of the corresponding nitroamino compounds. The coupling components may be phenols, naphthols, naphtholsulphonic acids, naphthylamines and their sulphonic acids, aminonaphthols, their sulphonic acids or N-substituted derivatives, arylpyrazolones and their sulphonic or carboxylic acids, acetoaceticarylamides and monoazo compounds e.g. p-nitroaniline --> (acid) H acid. They dye wool in various shades fast to washing and milling. In examples dyes from the following components are described: 1-N-ethyl - N - 3<1> - amino - 4<1> - methylbenzoylamino - 4 - aminobenzene, 1 - N - dodecyl - N - 4<1> - aminobenzoylamino - 4 - aminobenzene, 1 - N - cetyl - N - 3<1> - or 4<1> - aminobenzoylamino-4 - aminobenzene, 1 - N - octadecyl - N - 4<1> - aminobenzoylamino - 4 - aminobenzene; coupling components; 1-(4<1>-sulphophenyl)-3-methyl-5-pyrazolone, salicylic acid, N-phenyl-2 : 8 : 6 - acid, 2 - naphthol - 6 : 8 - disulphonic acid, N - b - hydroxyethyl - 2 : 8 : 6 - acid, 2 : 8 : 6 - acid, 1 - (2<1> : 5<1> - dichloro - 4<1> - sulphophenyl)-3-methyl-5-pyrazolone, 1-naphthol-4-sulphonic acid, 1-naphthylamine-4-sulphonic acid, 2-naphthol-6- or 8-sulphonic acid, 1-phenylaminonaphthalene-8-sulphonic acid, N-acetyl-2 : 8 : 6-acid, 2- or 1-naphthol-3 : 6-disulphonic acid, N-acetyl H acid, N-acetyl J acid, 2-amino-8-naphthol-3 : 6-disulphonic acid. The diazo components may be made by nitrating a benzoylalkyl aniline and reducing either one or both nitro groups, thus 1-N-ethyl-N - 3<1> - amino - 4<1> - methylbenzoylamino - 4 - aminobenzene is made by nitrating N-ethyl-N-4<1>-methylbenzoylaniline (obtained from N-ethyl-N-phenylurea chloride and toluene in presence of aluminium chloride) and reducing. The dinitro compound yields 4-nitroethylaniline and 3-nitro-4-methylbenzoic acid on hydrolysis with dilute sulphuric acid. The higher alkyl compounds required as starting materials are made by condensing a long-chain alcohol with an aromatic primary amine in presence of the amine hydrochloride and then with a nitrobenzoyl chloride. According to the Provisional Specification the diamines are of the second general formula above when R2 = alkyl.