GB632944A - Manufacture of disazo dyestuffs of the pyrazolone series - Google Patents

Abstract

Metallizable disazo dyestuffs, of the general formula <FORM:0632944/IV (c)/1> wherein X represents a CO or CS group, Y an alkyl (e.g. methyl), phenyl, carboxyl or converted carboxyl (e.g. ester or amide) group and A the radical of an aromatic amine free from further azo p groups (which radical, however, should not be the same as the radical of the nitrated diazo compound of 1-amino-2-naphthol-4-sulphonic acid), are manufactured by coupling one molecular proportion each of the nitrated diazo compound of 1-amino-2-naphthol-4-sulphonic acid and of any desired but different diazotized aromatic amine (free from azo groups) in either order, in a slightly acid, neutral or slightly alkaline medium, with a condensation product of phosgene or thiophosgene and two molecular proportions of an aminoaryl pyrazolone of the general formula <FORM:0632944/IV (c)/2> or by the action of phosgene or thiophosgene on a mixture of the aminoazo dyestuffs obtained from the nitrated diazo compound of 1-amino-2-naphthol-4-sulphonic acid and any desired different diazotized aromatic amine (free from azo groups) and an aminoaryl pyrazolone of the aforesaid general formula, the reaction being continued until the primary amino groups disappear. The amines corresponding to the radical A may be unsubstituted or substituted (e.g. by halogens or alkyl, hydroxy, alkoxy, nitro, acylamino, carboxy, carbamino or sulphonic acid groups), and advantageously contain, in o-position to the amino group, a metallizable group or substituent convertible thereto. The products dye cellulose fibres (e.g. cotton or regenerated cellulose) in orange, red, reddish brown and violet brown tints, and may be treated in substance or on the fibre with agents yielding metals, e.g. copper or chromium. Examples, illustrate both of the alternative processes, and a table gives the properties of further dyestuffs. A sample has been furnished under Sect. 2 (5) of the dyestuff produced by coupling 1-diazo-6-nitro-2-naphthol-4-sulphonic acid with the thiourea of 1 - (41-aminophenyl) - 3 - methyl - 5 - pyrazolone and coupling the resulting monoazo dyestuff with diazotized 5-nitro-2-aminobenzoic acid. The Specification as open to inspection under Sect. 91 comprises also the manufacture of (a) polyazo dyestuffs in which the radical A in the general formula above contains further azo groups; (b) dyestuffs in which X in the general formula above represents a cyanuryl radical; (c) dyestuffs in which the linkage-NH-X-NH-is connected in m-positions relative to the pyrazolone nuclei; and (d) dyestuffs in which the linkage -NH-X-NH- is replaced by -Zn-NH-X-NH-Zn-, where Z represents a m- or p-phenylene or m- or p-benzoylamino (-NH-CO-C6H4-) radical and n is zero or one. Additional examples and lists of components illustrate these features. This subject-matter does not appear in the Specification as accepted.