GB907382A - Disazo and trisazo dyestuffs and nickel complexes thereof - Google Patents

Abstract

6 - Nitro - 1:2-naphthoquinone-4-mono- and 4:8-disulphonic acids are prepared by oxidising the diazo-oxide of 1-amino-2-hydroxy-6-nitro-naphthalene-4-mono- or 4:8-disulphonic acid with, for example, chlorine, bromine or sodium chlorate and hydrochloric acid. The disulphonic acid may also be prepared by treating 6 - nitro - 2-amino-naphthalene-4:8-disulphonic acid with chlorine in 3% aqueous hydrochloric acid. N : N - bis[1:2-di-oxo-4:8-disulphonaphthyl-(6)]-urea is prepared by reducing 6-nitro-1:2-naphthoquinone - 4:8 - disulphonic acid to 6-amino - 1:2 - dihydroxy-naphthalene-4:8-disulphonic acid reacting this with phosgene and treating the urea formed, in acid solution, with an excess of sodium nitrite. Specifications 660,447, 721,495, 790,386, 820,476, 837,996, 866,914, 907,383 and 907,384 are referred to.ALSO:The invention comprises dyes of formula: <FORM:0907382/IV (b)/1> wherein R is a monoazo dye radical, B is an azo, azoxy, urea, secondary or tertiary triazinylamino, terephthaloylamino or fumaroylamino bridge member, X1 is a hydrogen atom or a sulphonic acid group, R1 is an aromatic radical containing Y1 in o-position to the azo bridge and Y1 is a metal-complex forming a group other than hydroxyl or alkoxy and the nickel and copper complexes thereof. The invention also comprises a process for the preparation of azo dyes wherein an aromatic or heterocyclic hydrazine compound or the corresponding N-b -sulphonic acid having in o-position to the hydrazine group a substituent capable of forming a metal complex or a substituent or atom convertible thereto under metallising conditions is reacted with a 6-nitro-or-acylamino-1 : 2-naphthoquinone-4- or - 8-mono- or -4 : 8-disulphonic acid, the dye coppered or nickelled if desired, the 6-nitro-or-acylaminogroup converted into an azo, azoxy, urea, secondary or tertiary triazinylamino, terephthaloylamino or fumaroylamino bridge member by reductively linking the nitro group to form an azo or azoxy group, by reduction of the nitro group or saponification of the acylamino group to an amino group which is diazotized and coupled with an azo component or reacted with phosgene, a di- or tri-halotriazine, terephthaloyl or fumaroyl chloride or first with phenyl chloroformate to form the phenylurethane which is then reacted with a 1-hydroxy-2-azo-6-aminonaphthalene sulphonic acid to form the urea. In a modification of the process the quinone p reactant is replaced by the corresponding 1-oxime (or 1-nitroso-2-hydroxy compound). The 1-hydroxylamino-2-azo compound formed in the first stage is further reacted with sodium nitrite and hydrochloric acid to give a 1-hydroxy-2-azo-compound which is further reacted as above. The dyes give blue shades on cellulose fibres. In Examples: (1) 6-nitro-1 : 2-naphthoquinone-4-sulphonic acid is reacted with 2-hydrazinonaphthalene-3: 6-disulphonic and the monoazo dye is oxidatively coppered and reduced using glucose in alkaline medium; (2) 6-nitro-1-nitroso-2-naphthol-4-sulphonic acid is reacted with phenylhydrazine-2: 5-disulphonic acid, the monoazo dye formed is treated with sodium nitrate and hydrochloric acid, oxidatively coppered and linked by reduction; (3) 6-nitro-or-acetylamino- 1 : 2-naphthoquinone-4-sulphonic acid is reacted with 2-hydrazinonaphthalene-3:6:8-trisulphonic acid, the nitro group reduced with sodium sulphide or the acetylamino group hydrolysed, the aminoazo dye reacted with phosgene to form the disazo dye which is oxidatively coppered. Further examples are specified. Specifications 660,447, 721,495, 790,386, 820,472, 837,996, 866,914, 907,383 and 907,384 are referred to.