Patent GB-766554-A (GB)
Title: Metal complex forming azo dyestuffs
IPC: C09B31/16
Filed: 1953-12-03
Abstract: 4 - Amino - 5 - hydroxy - benzoxathiol - s - dioxide-7-sulphonic acid is prepared by reducing the monoazo dyestuff from diazotized 1-aminobenzene-3-sulphonic acid and 5-hydroxy-benzoxathiol - s - dioxide - 7 - sulphonic acid by means of sodium bisulphite in acid medium.  Specifications 731,495 and 637,404, [Group IV (c)], are referred to.ALSO:The invention comprises metallizable azo dyestuffs of formula:-<FORM:0766554/IV(b)/1> wherein R is methylene, ethylene or o-arylene, -N=N-R1 in a diazo radical comprising an aromatic or pyrazole nucleus to which the diazo group is attached in ortho-position to a metal complex forming group, B is a benzene or naphthalene nucleus and n is 1 or 2; and the metal complexes thereof. The metalfree dyestuffs may be obtained by coupling a diazo or tetrazo compound bearing in ortho position to the diazo group a metal complex forming group with derivatives of 1:4-benzo- or -naphtho-quinone one hydroxy group of which is connected with a -SO2- group in adjacent position by means of a methylene, ethylene or o-arylene linking member to form a cyclic ether sulphone.  The diazo or tetrazo compounds may already contain azo groups. Alternatively a cyclic ether sulphone as described above but containing an amino group in the position between the hydroxy and -SO2- groups is diazotized and coupled with aromatic or pyrazole components which may already contain azo groups and which couple ortho to a metallizable grouping.  The heavy metal complexes of the dyestuffs may be prepared by known methods in substance or on the fibre.  The metallized and unmetallized dyestuffs may be used to dye natural or regenerated cellulose and animal or polyamide fibres in red, blue and green shades.  The cyclic ether sulphones, and derivatives thereof, used as starting materials are described in Specification 731,495 [Group IV(b)]. In examples the following metalfree dyestuffs are prepared, chromium and cobalt complexes of certain of them being prepared in substance: 4-amino-5-hydroxybenzoxathiol-S-dioxide is diazotized and coupled with 1-phenyl- or -(21- or -31-chlorophenyl)- or -(21:51-dichlorophenyl)-or -(31-nitrophenyl)-3-methyl-5-pyrazolone, p-tert.-butylphenol, 3-hydroxydiphenylene oxide, 2-naphthol, 1-naphthol-4- or -5-sulphonic acid, 1-naphthol-4:8-disulphonic acid, 2-naphthol-6-sulphonic acid, and 41-hydroxy-naphtha-(21, 1 1: 4, 5)-oxathiol-S-dioxide; 4-amino-5-hydroxy-benzoxathiol-S-dioxide-7-sulphonic acid (see Group IV(b)) --> 2-naphthol; 5-hydroxybenzoxathiol-S-dioxide is coupled with the diazo compounds from 1-amino-2-methoxy-5-chlorobenzene and anthranilic acid; 41-hydroxy-naphtho-(21, 11 : 4, 5)-oxathiol-S-dioxide is coupled with diazo or tetrazo compounds from 1-amino-2-hydroxy-4-nitro- or -5-chloro-benzene, 4-hydroxy-3-amino - azobenzene-41-sulphonic acid, 1 - amino 2-hydroxy-3:5-dinitrobenzene, 5-sulphonamido- or -methylsulphonamido- or - dimethylsulphonamido - 2 - hydroxy - 1 - aminobenzene and 4:41-diamino-3:31-carboxymethoxy-diphenyl; and 1-amino-2-methoxy-5-chlorobenzene --> 3-hydroxy-6-chlorophenoxthin-S-dioxide.  Specification 637,404 also is referred to.