Patent GB-442778-A (GB)
Title: Process for the manufacture of azodyestuffs
IPC: C09B35/28
Filed: 1934-08-14
Abstract: Azo dyes; azo dyes, forming upon the material.  --Azo dyestuffs are manufactured by condensing one molecular proportion of a diaminonaphthalenesulphonic acid containing the amino groups neither in onor in peri-position to each other, with two molecular proportions of 4-nitrobenzoyl chloride, reducing the nitro groups, tetrazotizing and coupling with one molecular proportion of 1-(3<1>-aminophenyl)-3-methyl-5-pyrazolone or of 1-(3<1>-aminophenyl)-5-pyrazolone-3-carboxylic acid or an alkyl ester thereof and with one molecular proportion of one of the same coupling components or of a yellow component, free from a diazotizable amino group, selected from the group consisting of phenols, phenol ethers, pyrazolones or the sulphonic or carboxylic acids thereof, b -ketocarboxylic acid arylamides and methyl ketol, the coupling being performed in any sequence. Alternatively, one molecular proportion of a monoacyl derivative of a diaminonaphthalenesulphonic acid of the type specified is condensed one molecular proportion of 4-nitrobenzoyl chloride, the nitro group is reduced, the amino group is diazotized, the diazo compound is coupled with a yellow component of the type specified, the acyl group is split off, the amino group is 4-nitrobenzoylated, the nitro group is reduced to the amino group, and the aminoazo compound is diazotized and coupled with one molecular proportion of 1-(3<1>-aminophenyl)-3-methyl-5-pyrazolone or 1-(3<1>-aminophenyl)-5-pyrazolone-3-carboxylic acid or an alkyl ester thereof.  Instead of the aminophenylpyrazolone compounds specified there may be used the corresponding nitro compounds, the nitro group being subsequently reduced.  In examples: (1) 2 : 6-diaminonaphthalene-4-sulphonic acid is reacted with 4-nitrobenzoyl chloride in the presence of sodium carbonate, the product is reduced and the resulting di-p-aminobenzoyl-2 : 6-diaminonaphthalene-4-sodium sulphonate is tetrazotized and coupled with 2 mols. of 1 - (3<1>-aminophenyl) - 3 - methyl - 5 - pyrazolone; the product dyes cotton greenish-yellow shades which are not altered by diazotization on the fibre and developing with 1-phenyl-3-methyl-5-pyrazolone, and which yield a yellowish-orange with b -naphthol; (2) di-p-aminobenzoyl-1 : 4-diaminonaphthalene-6-sodium sulphonate, prepared by a method analogous to that of (1), is tetrazotized and coupled with 1 mol. of 1-(6<1>-sulpho - 2<1>-naphthyl) - 3 - methyl - 5 - pyrazolone and 1 mol. of 1-(3<1>-aminophenyl)-3-methpl-5-pyrazolone; the product dyes somewhat more reddish shades than that of (1) ; (3) 1-(4<1>-aminobenzoyl)-4-formyldiaminonaphthalene-6-(or-7-) sodium sulphonate, obtained by reacting 1-amino-4-formylaminonaphthalene-6- (or -7-) sulphonic acid with 4-nitrobenzoyl chloride in the presence of sodium carbonate and reducing the product, is diazotized and coupled with 1-(4<1>-sulphophenyl)-3-methyl-5-pyrazolone, the product, is saponified and condensed with 4-nitrobenzoyl chloride, the nitro group is reduced and the product is diazotized and coupled with 1-(3<1>-aminophenyl)-3-methyl-5-pyrazolone; the product has properties similar to that of (1); (4) di-4-aminobenzoyl-1 : 4-diaminonaphthalene-6-sodium sulphonate is tetrazotized and coupled with 2-mols. of 1-(3<1>-nitrophenyl)-5-pyrazolone-3-carboxylic acid, the nitro groups being subsequently reduced; the product dyes cotton yellow shades which yield an orange on diazotizing and coupling with b -naphthol and a reddish-yellow with 1-phenyl-3-methyl-5-pyrazolone. Samples have been furnished under Sect. 2 (5) of dyestuffs prepared as follows: (A) 1 : 4-naphthylenediamine-6- (or 7-) sulphonic acid is condensed with 4-nitrobenzoyl chloride in the presence of sodium carbonate and the product is reduced, tetrazotized and coupled with salicylic acid and 1-(3<1>-aminophenyl)-3-methyl-5-pyrazolone; (B) the salicylic acid of (A) is replaced by acetoacetic acid anilide. Dyed specimens show the shades obtained on cotton and the effect of diazotization on the fibre and coupling with 1-phenyl-3-methyl-5-pyrazolone and with b -naphthol. Specifications 1441/11, 7303/13, and 3557/14, [all in Class 2 (iii)], are referred to.  The Specification as open to inspection under Sect. 91 comprises also the manufacture of azo dyestuffs by condensing one molecular proportion of a monoacyldiaminonaphthalenesulphonic acid of the kind referred to above with one molecular proportion of nitrobenzoyl chloride, reducing the nitro group, diazotizing, coupling with a yellow component free from a diazotizable amino group, splitting of the acyl group by saponification, diazotizing and coupling with one molecular proportion of 1-(3<1>-aminophenyl)-3-methyl-5-pyrazolone or of 1-(3<1>-aminophenyl)-5-pyrazolone-3-carboxylic acid or an ester thereof.  This subject-matter does not appear in the Specification as accepted.