Patent GB-823742-A (GB)
Title: Monoazo-benzoxathiol-s-dioxide dyestuffs and metal complexes thereof
IPC: C09B45/14
Filed: 1957-02-25
Abstract: 6 - Hydroxy - 5 - acetylamino - benzoxathiol-S-dioxide is made by strongly reducing, e.g. with divalent tin chloride, titanium chloride or sodium dithionite, the dyestuff obtained by demetallizing the dyestuff 6-chloro-5-amino-benzoxathiol - S - dioxide (see Specification 753,261) --> 2 - naphthol - 3,6 - disulphonic acid which has been coppered as in Specification 388,332, [Group IV], so that the Cl atom is replaced by OH and 4-hydroxy-S-acetylamino-benzoxathiol-S-dioxide is made by a similar process starting from 5-aminobenzoxathiol-S-dioxide but using the coppering process of Specification 660,447, [Group IV (c)], to introduce the 4-hydroxy group.  The hydrolysed products are used as dyestuff intermediates (see Group IV (c)). Specifications 755,853, 758,016, [both in Group IV (c)], 806,709 and 819,174, [Group IV (c)], also are referred to.ALSO:The invention comprises dyestuffs of formula <FORM:0823742/IV(c)/1> where one of the radicles X is H and the other X is OH or a group convertible thereto during metallization and R is the residue of a coupling component, free of COOH or SO3H groups, and bearing an OH group in an ortho position to the azo group.  The invention also includes metal complexes of the above dyestuffs.  The dyestuffs may be made by conventional diazotization and coupling processes and metallization is effected in the usual fashion. Cobalt and chromium are preferred metals.  Indicated as coupling components are acetic acid arylides, pyrazolones, naphthols, acylaminonaphthols, acylalkylaminonaphthols, 2,4 - dihydroxyquinoline, 1,3 - dihydroxy - isoquinoline, naphthohydroquinone - methylene - sulphonether and phenols.  The dyestuffs dye wool and similar materials by single-bath or after-chroming processes.  The metal complexes 1,2-cobalt and chromium complexes being preferred, dye and print wool, silk, leather and polyamide and polyurethane fibres.  Mixtures of dyes of the above formula may be metallized, as may mixtures of dyestuffs containing one dyestuff of the above formula and any other metallizable dyestuff.  In examples which illustrate the preparation of the metal-free and metal-containing dyestuffs and their use in dyeing wool in yellow, red, blue, grey and brown shades, both diazo components and several of the above indicated coupling components are used, representative being 1-(21,51-dichloro - and 31 - p - chlorobenzenesulphonyl-amino) - phenyl - 3 - methyl - 5 - pyrazolone, 2-naphthol - 6 - sulphonamide, 41 - hydroxy - naphtho - (21,11,4,5) - oxathiol - S - dioxide, acetoacetic acid anilide and 1-(N-methyl-N-methylsulphonyl) - amino - 7 - naphthol.  The following dyestuffs are obtained during the preparation of starting materials: 6 - chloro - 5 - amino - benzoxathiol - S - dioxide \>2 - naphthol - 3,6 - disulphonic acid which is coppered as in Specification 388,332, [Group IV], so that the Cl atom is exchanged for OH and the product is demetallized, and 5-amino-benzoxathiol - S - dioxide \>2 - naphthol - 3,6 - disulphonic acid which is oxidatively coppered as in Specification 660,447, to introduce a 4-hydroxy group, and the product demetallized.  Specifications 753,261, [Group IV (b),] 755,853, 758,016, 806,709 and 819,174 also are referred to.