Patent GB-784613-A (GB)
Title: New disazo-dyestuffs, copper complexes thereof, and processes for making them
IPC: C09B35/28
Filed: 1954-10-13
Abstract: The invention comprises dyestuffs of formula <FORM:0784613/IV (b)/1> where R1 is the residue of a phenol-o-carboxylic acid, R2 and R3 are benzene residues in which the C atoms bound to the azo link and the [-CO-HN-]- group are separated from one another by at least one C atom, R4 is a benzene residue which contains an SO3H, COOH or OCH2COOH group and UV is OH, COOH or OAlk oto the azo link, and the copper complexes thereof.  They may be made by coupling a diazo-compound of an azo dyestuff of formula <FORM:0784613/IV (b)/2> with an appropriate J acid derivative, and if desired, coppering the product or by coupling a diazo-compound of an azo dyestuff of formula <FORM:0784613/IV (b)/3> or a copper complex thereof, with a phenol-o-carboxylic acid, and, if desired, coppering the product. Dyestuffs of formul  R1-N=N-R2-CO-HN-R3(UV)NH2 and R1-N=N-R2-NH-CO-R3(UV)NH2 may be used as starting material, the former being obtained by coupling a tetrazo-compound of a diamine of formula H2-N-R2-CO-HN-R3(UV)NH2, in which the NH2 groups are not oto the CONH groups, advantageously in an alkaline medium, with a phenol-o-carboxylic acid such as 6-chloro- and methyl-1-phenol-2-carboxylic acid and especially salicylic acid. Preferably, and especially in R3, the NH2 and CONH groups are pto each other.  Diamines specified are 1 - amino - 4 - (31-and 41 - aminobenzoylamino)-and (31-methyl- and chloro-41-aminobenzoylamino) - 2 - carboxy-, oxy- and methoxybenzenes.  The dyestuffs of formula R1-N=N-R2-NH-CO-R3(UV)NH2 are made by condensing a compound of formula R1-N=N-R2 with an acid halide of formula Halogen-OC-R3(UV)NO2, the acid halide group not being oto NO2 and preferably the groups NO2, UV and Halogen-OC are in 4,3,1-positions, and reducing the NO2 group.  Compounds of formula R1-N=N-R2NH2 mentioned are 4-amino-41-oxy-1,11-azobenzene-31-carboxylic acids which may contain in R1, or advantageously in R2, further substituents, e.g. 4 - amino - 41 - oxy - 1,11 - azobenzene - 31 - car - boxylic acid and its 2-methyl-5-methoxy- and 2-chloro-derivatives.  Advantageously the acid halides used are 4-nitro-3-alkoxybenzene-1-carboxylic acid chlorides with alkoxy groups of at most 2 carbon atoms. 8-Naphthol-sulphonic acids specified are 2-(41-methyl- and chlorophenylamino)- and phenylamino - 8 - naphthol-6,31 - di-, (21 - methylphenylamino) - 8 - naphthol - 6,41 - di-, (41 - carboxymethoxyphenylamino) - 8 - naphthol - 6 - mono- and phenylamino - 31 - carboxy - 8 - naphthol - 6 - monosulphonic acids.  Dyestuffs of formula <FORM:0784613/IV (b)/4> are of especial use in the second of the above methods of preparation and they are made either by diazotizing an amine of formula X-R3(UV)NH2, where X is a substituent not oto NH2 convertible to an amino group, e.g. a nitro or acetylamino group, and coupling with an appropriate 8-naphthol-sulphonic acid, converting X to NH2, acylating the amine with a m- or preferably p-nitrobenzoyl halide, and reducing the nitro group or by diazotizing a compound of formula O2N-R2-CO-HN-R3(UV)NH2, coupling with an appropriate naphthol-sulphonic acid and reducing the nitro group.  Coppering is effected in known manner and may be effected in R1 as well as at the azo link.  When products are derived in which R1 is free of copper it is of advantage partially to decopper the product which contains 2 atoms of Cu, e.g. by treatment with HCl at raised temperature.  The dyestuffs and their complexes dye fibres of natural and regenerated cellulose, e.g. cotton, linen and artificial silk.  When metal-free or partially coppered products are used in dyeing they may be metallized, advantageously coppered, by treatment on the fibre or in the dyebath, or partially on the fibre and partially in the dyebath. Examples are provided illustrating the preparation of the dyestuffs from certain of the above indicated reactants and the use of the dyestuffs in dyeing cotton in brown shades. Specification 644,883 is referred to.