GB781086A - New metalliferous disazo-dyestuffs containing a fused thiazole ring and process for making them - Google Patents

Abstract

The invention comprises dyestuffs of formula <FORM:0781086/IV (b)/1> where R is a benzene residue fused on to the thiazole ring, R1 is a benzene residue bound to the thiazole ring in para-position relatively to the azo linkage, R2-O- is a residue of a middle component of the benzene or naphthalene series in which the two azo linkages are in para-position relatively to the azo linkage between R2 and R3, R3-O- is a residue of a 1-amino-8-naphthol mono-sulphonic acid substituted in the amino group and bound in the 7-position to the azo linkage and Me is Ni or advantageously Cu. They are made by treating dyestuffs of formula <FORM:0781086/IV (b)/2> in conventional fashion or as in Specification 644,883 with nickel and copper yielding agents under dealkylating conditions. The metal-free dyestuffs may be made by coupling a diazo compound of an amine <FORM:0781086/IV (b)/3> advantageously in a weakly acid to weakly alkaline medium, with a middle component <FORM:0781086/IV (b)/4> (although if the latter has a low capacity for coupling it is preferably used as its o -methane sulphonic acid with subsequent elimination of the acid group), diazotizing the resultant aminomonoazo-dyestuff and coupling in an alkaline medium with an end component H-R3-OH, optionally in the presence of agents such as pyridine and picoline. Specified initial components are dehydrothiotoluidine and monosulphonic acids thereof obtained on treatment with conc. sulphuric acid or on thermal rearrangement of its acid sulphate and disulphonic acids thereof obtained by thermal rearrangement of the acid sulphate of the monosulphonic acid obtained above by sulphuric acid treatment. Specified middle components which advantageously contain methoxy or ethoxy groups as the o-alkoxy group are 1-amino-2-methoxy-benzene and its 5-methyl derivative, 1-amino-2,5-dimethoxy- and diethoxy-benzene and 1 - amino - 2 - methoxy - orethoxy - naphthalene-6- or -7-sulphonic acids. Indicated end components are 1-amino-8-naphthol-monosulphonic acids, the amino group of which may be substituted to provide mono- or di-alkylamino groups with low molecular weight alkyl residues, e.g. methyl or ethyl groups, arylamino groups, especially phenylamino and alkylphenylamino groups, mono- and di-(oxyalkyl)-amino groups, e.g. mono- and di-(b -oxyethyl)-amino groups and acylamino groups such as acetyl-, benzoyl- and p-chloro-benzoyl-amino groups. Advantageously end components are used derived from 1-amino-8-naphthol-4-sulphonic acids. Advantageously the final dyestuff contains at least two groups imparting solubility in water, e.g. sulphonic acid groups. The metallized dyestuffs dye materials such as wool, silk, leather and especially cotton, linen, artificial silk and regenerated cellulose. Cotton is dyed in green tints. Examples are provided illustrating the use of certain of the above specified components in the preparation of the metallized dyestuffs, the end components used being 1-acetyl-, benzoyl- or -phenyl-amino-8-naphthol-4-sulphonic acid.