Patent GB-358136-A (GB)
Title: Process for the manufacture of azo dyestuffs
IPC: C09B62/66
Filed: 1930-07-08
Abstract: Azo dyes are obtained by coupling in an acid medium a 2-naphthylamine- or 2 : 8-aminonaphtholsulphonic acid or an N-substituted derivative thereof with a diazo compound of an amine of the general formula <FORM:0358136/IV/1> in which R1 is an alkyl group carrying at least one OH or O-SO3H group and R2 is an aryl or substituted aryl group, and in which the benzene nucleus may carry further substituents other than sulphonic or carboxylic groups, such as NO2, NH2, or NH-CO-CH3.  The products are more soluble than the corresponding known dyes in which the sulphonalkylarylide group does not contain OH or O-SO3H as substituent.  The following examples are specified: (1) The dyestuff 4-nitraniline-2-sulphoxyethylanilide --> (acid) 2 : 8 : 6-acid dyes wool a fast blue.  (2) The dyestuff 4-nitraniline-2-sulphoxyethylanilide --> (acid) methyl-2 : 8 : 6-acid dyes wool a fast blue, somewhat greener than the blue of (1).  (3) The dyestuff 4-aminoaniline-2-sulphoxyethylanilide --> (acid) 2 : 8 : 6-acid obtained by alkaline sodium sulphide reduction of the dyestuff in (1) gives a bordeaux red dyeing.  (4) By acetylating the free amino group of the dyestuff in (3) the shade is displaced towards red.  (5) The dyestuff 4-nitraniline-2-sulphanilide-N-oxyethyl sulphuric acid ester --> (acid) 2-methylaminonaphthalene-7-sulphonic acid dyes wool clear reddish blue; if the coupling component is replaced by 2 : 6- or 2 : 7-naphthylaminesulphonic acid redder shades are obtained.  (6) The dyestuff 4-nitraniline-2-sulphanilide-N-oxyethyl sulphuric acid ester --> (acid) 2 : 8 : 6-acid dyes wool marine blue; if the coupling component is replaced by methyl-2 : 8 : 6-acid the shade is greener; the dyestuff 4-nitraniline-2-sulpho-21-anisidide-N-oxyethyl sulphuric acid ester --> (acid) methyl-2 : 8 : 6-acid is blueish green; the corresponding 21- and 41-toluidides and 21- and 41-chloranilides gives shades similar to those obtained with the anilide; if the coupling component is replaced by 2-methylaminonaphthalene-7-sulphonic acid marine blue dyeings are obtained.  (7) The nitro groups in the dyestuffs of (6) may be converted into amino groups by alkaline sodium sulphide reduction; the products dye wool from an acid bath blueish red or reddish violet; on acetylating the amino groups the shades are displaced towards red, the same dyestuffs being also obtainable by diazotizing the 4-acetylaminoaniline-2-sulpharylide-N-oxyethyl sulphuric acid esters and coupling with the components in acid solution, and 2 : 6- or 2 : 7-naphthylaminesulphonic acids may also be used as coupling components.  Aniline-2-sulpharylide-N-oxyalkyl sulphuric acid esters and their 4-nitro, 4-amino, and 4-acetylamino derivatives are obtained by the action of sulphuric acid on the corresponding sulphoxyalkylarylides and isolated as well crystallized sodium salts. 4-Nitraniline-2-sulphoxyethylanilide and the corresponding 21-anisidide, 21- and 41-toluidides, an 21-and 41-chloranilides are obtained by the action of ammonia under pressure on the products of reaction of 4-nitro-1-chlorobenzene-2-sulphochloride on oxyethylaniline, oxyethyl-21-anisidine, oxyethyl-21-and 41-toluidines, and oxyethyl-21- and 41-chloranilines respectively. Oxyethyl-21-anisidine, oxyethyl-21- and 41-toluidines, and oxyethyl-21- and 41-chloranilines are obtained by heating the corresponding primary aryl amines with glycolchlorohydrin in water in presence of an acid-binding agent.