Patent GB-599834-A (GB)
Title: Improvements in or relating to the manufacture of azodyestuffs
IPC: C09B29/20
Filed: 1945-07-13
Abstract: Azo dyestuffs are formed in substance or on the fibre by coupling an arylide of an orthooxycarboxylic or acylacetic acid with a diazo derivative of 7-amino-indazol in which the benzene nucleus may carry substituents, such as halogen, alkyl, alkoxy, aryloxy, acylamino, nitro, sulphone, sulphamido or arylazo groups, which do not confer solubility in water.  The coupling may be effected in the presence of a metallizing agent, or the dyed fibre may be treated with a copper salt in presence of an organic base containing at least one oxyalkyl group, e.g. mono-, di- and tri-ethanolamines, propanolamine and diethyl-oxyethylamine.  The following examples are given: (1) cotton is foularded in a bath containing the b -naphthylamide of 2,3-oxynaphthoic acid and developed in a diazotized solution containing 7-amino-indazol to which is added neutral copper acetate and magnesium sulphate; (2) the 7-amino-indazol of (1) is replaced by 4-chloro-7-aminoindazol, obtainable by diazotizing 3-nitro - 6 - chloro - 2 - acetylaminotoluene, boiling, and reducing the 4-chloro-7-nitro-indazol so obtained; (3) a mixture of 7-amino-indazol and 4-chloro-7-amino-indazol is diazotized and coupled with b -naphthylamide of 2,3-oxynaphthoic acid on cotton, and the dyeing after-treated with a solution containing copper sulphate and monoethanolamine; (4) the previous example is repeated using 4-nitro-7-amino-indazol, obtained by nitrating 7-amino-indazol in glacial acetic acid and then saponifying; (5) example (3) is repeated using 4-diethylsulphamido-7-amino-indazol obtained by (a) treating 1 - acetylamino - 2 - methyl - 3 - chloro - 6 - nitrobenzene with sodium sulphide and sulphur, (b) chlorinating the 2,21-dimethyldiphenyl sulphide so formed to yield 2-methyl-3 - acetylamino - 4 - nitrobenzene sulphochloride, (c) treating with diethylamine to give 2 - methyl - 3 - acetylamino - 4 - nitrobenzene - diethylsulphamide, (d) saponifying, (e) diazotizing to give 7-nitro-4-diethylsulphamidoindazol and then (f) reducing with iron powder and acetic acid; (6) example (3) is repeated using 4-methoxy-7-amino-indazole as base and the anilide of 2,3-oxynaphthoic acid as coupling agent, the former being prepared by (a) heating 3 - nitro - 6 - chloro - 2 - aminotoluene with methyl alcohol and potash to give 3-nitro-6-methoxy-2-aminotoluene which is then (b) diazotized and poured into hot sodium acetate solution to give 4-methoxy-7-nitroindazol which is finally (c) reduced with iron powder and acetic acid; (7) example (3) is repeated using 5 - chloro - 7 - amino - indazol prepared by diazotizing 3-nitro - 5 - chloro - 2 - aminotoluene, pouring into a hot solution of sodium acetate, and reducing with iron powder and hydrochloric acid; (8) example (3) is repeated using 4 - benzoylamino - 5 - methyl - 7 - amino - indazol, which is prepared by reducing 4-nitro-5-methyl-indazol with iron powder and acetic acid, benzoylating the amino group, nitrating in the presence of acetic acid, and again reducing.  A Table is also included showing the various colours obtained with a number of specified bases and coupling agents before and after coppering. Specification 518,987 is referred to.  The Specification as open to inspection under Sect. 91 refers generally to the production of dyestuffs, in substance or on the fibre, from a coupling agent having a substantive character and an amino-indazol of the formula <FORM:0599834/IV/1> in which X is a hydrogen or halogen atom, Y is hydrogen or an alkyl, aralkyl or cycloalkyl group, and in which the benzene nucleus may carry substituents which do not confer solubility in water.  The dyestuffs may then be converted into their metalliferous complexes.  Examples given include the diazotizing of 6-amino-indazol and coupling with b -naphthylamide of b -oxynaphthoic acid in the presence of neutral copper acetate; diazotizing 3-chloro-6-amino-indazol and coupling with b -naphthylamide of b -oxynaphthoic acid in the presence of copper acetate; diazotizing 6-amino-indazol, coupling with b -naphthylamide of b -oxynaphthoic acid and coppering with copper sulphate in presence of monoethanolamine; diazotizing 3 - chloro - 6 - amino - indazol, coupling with b -naphthylamide of b -oxynaphthoic acid and coppering with copper sulphate in presence of triethanolamine; in other similar examples the following amino-indazoles are used, 5-chloro-6-amino-indazol, a mixture of 1- and 2 - methyl - 6 - amino - indazol, 4-amino - 7 - benzoylamino - indazol, o - chloroaniline --> 6 - amino - indazol, o - chloro - aniline --> 1- or 2-methyl-6-amino-indazol, 5- - amino - indazol, 6 - chloro - 5 - amino - indazol, o-nitraniline --> 6-amino-indazol.  A Table is given of many diazotizable bases and coupling components showing the colours obtained before and after coppering.  This subject-matter does not appear in the Specification as accepted.