Patent GB-682024-A (GB)
Title: Manufacture of trisazo dyestuffs
IPC: C09B35/40
Filed: 1950-07-18
Abstract: Substituted anilides of m- and p-aminobenzoic acids are made by (1) condensing a m-or p-nitraniline with m- or p-nitrobenzoyl chloride and reducing the two nitro groups in the product, or (2) condensing a m- or p-phenylene diamine with m- or p-nitrobenzoyl chloride and reducing the nitro group in the product.  The nitraniline may contain nuclear substituents, e.g. chlorine or other halogen, methyl or methoxy but not carboxylic acid groups; suitable compounds are listed.  The diamine may be similarly substituted, p-phenylene diamine monosulphonic acid being specified.  Examples are given of the production of 2 - amino - 5 - (p - aminobenzamido) toluene and 2 : 5 - dimethoxy - 4 - (p - aminobenzamido)-aniline by method (1).ALSO:The invention comprises trisazo dyestuffs of the formula <FORM:0682024/IV (c)/1> where R1, R2, R3 and R4 are benzene residues, the attachments to R2 and R3 being m- or p-; R1 contains a hydroxy group pto the azo linkage and carboxyl group oto the hydroxyl; R4 contains an o-oxy or o-alkoxy group or metallized derivative thereof; R3 is free from carboxylic groups; the azo groups are attached to the nucleus I oto the hydroxy groups.  These dyestuffs may be made by coupling resorcinol successively in either order with diazotized R4NH2 and the diazo compound of an amino-azo dyestuff R1-N=N-R2-CO-HN -R3-NH2. Alternatively salicylic acid or a substitution derivative thereof p  may be coupled with the diazo compound of an amino-azo dyestuff of the formula <FORM:0682024/IV (c)/2> Metallization may be effected by treating the final dyestuff or a metallizable intermediate thereof with an agent yielding metal, e.g. copper, chromium, nickel or cobalt.  Preferably conditions are chosen so that the salicylic acid grouping in R1 is not metallized.  Alternatively metallization may be carried out in the dyebath and/or on the fibre, e.g. as in Specifications 455,274 and 619,969.  The products are suitable for dyeing or printing animal and cellulosic fibres, e.g. wool, silk, leather, linen, cotton and regenerated cellulose. Substituents that may be present on the benzene nuclei are: R1, chlorine, methyl; R3, chlorine or other halogen, methyl, methoxy, sulphonic acid; R4, sulphonic acid, carboxylic acid or amide, sulphonamide, chlorine. The diazo compounds of R1-N= N-R2-CO-HN-R3-NH2 may be made by tetrazotizing a diamine H2N-R2-CO-HN-R3-NH2 and coupling with 1 mol. of salicylic acid or substitution derivative thereof.  The amino-diazo dyestuffs of the above formula may be obtained by coupling resorcinol successively in either order with diazotized R4NH2 and diazotized X-R3-NH2 (X=e.g., nitro or acylamino), converting X into NH2, condensing the product with m- or p-nitrobenzoyl chloride and reducing the nitro group. Alternatively, resorcinol may be coupled successively in either order with diazotized R4NH2 and diazotized O2N-R2-CO-HN-R3-NH2 and the nitro group then reduced.  Metallization may be carried out on the intermediates R4X --> resorcinol or the amino-diazo dyestuffs.  In the examples: (1) 4-(p-aminobenzamido)-aniline is tetrazotized and coupled first with salicylic acid (or its 4-methyl or 3-chloro derivative) and then with the coppered monoazo dyestuff 2-aminophenol-4-sulphonic acid --> resorcinol; (2) the diamine of (1) is coupled first with salicylic acid and then with the monoazo dyestuff 2-aminophenol-4-sulphonamide --> resorcinol or 2-amino-4-chlorophenol --> resorcinol; (3) 3-(m-aminobenzamido)-aniline is tetrazotized and coupled first with salicylic or cresotic acid and then with the monoazo dyestuff 3 - amino - 4 - oxybenzamide --> resorcinol; 2 - aminophenol - 4 - sulphonamide, 4 - chloro - 2 - aminophenol - 6 - sulphonic acid or 2 - methoxyaniline - 5 - sulphonic acid may also be used to make the monoazo intermediate; (4) 4 - (p - aminobenzamido) - 2 - methylaniline or -2 : 5-dimethoxyaniline is tetrazotized and coupled first with salicylic acid and then with the coppered monoazo dyestuff of (1); (5) 4-acetylamino-aniline is diazotized and coupled with the monoazo dyestuff 2-aminophenol-4-sulphonic acid --> resorcinol; the acetyl group is then hydrolysed off, the product condensed with p-nitrobenzoyl chloride and the nitro group reduced; the amino-disazo dyestuff is then diazotized and coupled with salicylic acid.  a further example is given of the dyeing of cotton with the product of (1).  Other suitable components are listed.