Patent GB-730547-A (GB)
Title: Process for the preparation of polyazo dyestuffs
IPC: C09B35/366
Filed: 1952-03-18
Abstract: The invention comprises: (1) the production of copper derivatives of polyazo dyestuffs of the formula <FORM:0730547/IV (c)/1> where R is the residue of a phenolsulphonic acid or a naphthol mono-, di- or tri-sulphonic acid attached oto its hydroxyl group and R1 is the residue of a coupling component, by coupling tetrazotized dianisidine in either order with 1 : 6 - dihydroxynaphthalene - 3 - sulphonic acid carrying the group R-N = N-in the 5-position (or its copper complex if R1 is an unsulphonated o-hydroxyaryl residue or is an enolic coupling residue) and with another coupling component, and coppering the product; and (2) the particular dyestuffs listed below obtainable by this process.  The monoazo intermediates are made by (1) coupling a diazotized aniline-sulphonic acid with O-acetyl-J acid, replacing the amino group by hydroxyl by the method of Specification 727,747, introducing an o-hydroxyl group into the p benzene nucleus by oxidative coppering (as in Specification 660,447) and hydrolysing the acyl group, or (2) coupling diazotized 1 - amino - 5 - acyloxynaphthalene - 7-sulphonic acid with a naphtholsulphonic acid; introducing a 2-hydroxyl group into the naphthalene nucleus by oxidative coppering and hydrolysis of the acyl group.  The monoazo dyestuffs may, if desired, be demetallized with mineral acids or alkali metal sulphides. Coupling of these monoazo intermediates may be carried out in the presence of pyridine and ammonia.  Coppering of the polyazo dyestuffs may be effected by heating with alkaline copper tetrammine complexes with or without organic bases or in the melt of alkali salts of aliphatic monocarboxylic acids with copper salts. The products dye cotton and regenerated cellulose in blue or grey shades.  In the examples the following dyestuffs are made and coppered: (1) 1 - naphthol - 3 : 6 - disulphonic acid \sM dianisidine --> copper complex of 1 : 6-dihydroxy - 5 - (21 - hydroxy - 41 - sulphophenylazo) - naphthalene - 3 - sulphonic acid; (2) as in (1) using the 51-sulpho-isomer; (3) as in (1) the second coupling component having as 5-substituent 11 - hydroxy - 41 - sulphonaphthyl - 21 - azo; (4) 1-(41-sulphophenyl)-3-methyl-5-pyrazolone \sM dianisidine --> copper complex of 1 : 6 - dihydroxy - 5 - (21 - hydroxy - 41 - sulphonaphthyl - 11 - azo) - naphthalene - 3 - sulphonic acid; (5) dianisidine \sQ 2 mols. of second coupling component of (1); (6) 1-naphthol-3 : 8-disulphonic acid \sM dianisidine --> second coupling component of (4); (7) 2-naphthol-4-sulphonic acid \sM dianisidine --> copper complex of 1 : 6 - dihydroxy - 5 - (11 - hydroxy - 31 : 61 - disulphonaphthyl - 21 - azo) - naphthalene-3-sulphonic acid; (8) 1-naphthol-3 : 6-disulphonic acid \sM dianisidine --> demetallized monoazo compound of (1) (in pyridine and ammonia). A further example is given of the dyeing of cotton with the product of (1).  A list shows further dyestuffs obtained by the process of the invention, including as additional first coupling components 1-naphthol-4-sulphonic acid, 2 - naphthol - 6 - sulphonic acid, chromotropic acid, N-acetyl-H acid, N-acetyl-J acid, N - benzoyl - J acid, 2 - naphthol, 1 - phenyl - 3 - methyl - 5 - pyrazolone and N - (p - carboxyphenyl) - g  - acid.  Other suitable components are specified.