GB858181A - Improvements in the production of diazapolymethine dyestuffs - Google Patents

Abstract

The invention comprises diazapolymethine dyestuffs having cations of the general formula: <FORM:0858181/IV (c)/1> wherein R is an alkyl or aryl group, Y is a divalent heteroatom or -NH-, -N (alkyl)-, -N (aryl)-, or -N (NH2)-, X is a divalent azomethine group substituted on the carbon atom, and R1 is the residue of a coupling compound. The dyestuffs may be obtained by subjecting hydrazones of the formula: <FORM:0858181/IV (c)/2> wherein X, Y, and R have the meanings indicated above, to an oxidizing coupling reaction with coupling components in the presence of oxidizing or dehydrogenating agents. Hydrazones mentioned include those of 3- methyl -5- anilino-1. 3. 4- thiadiazolone-(2), 3- methyl -5- phenyl-1. 3. 4- oxadiazolone- (2), 1-methyl -3- phenyl-4- nbutyl -1. 2. 4- triazolone- (5), 1 -methyl -3-phenyl -4- amino -1. 2. 4- triazolone- (5), 2-methylmercapto -4- methyl -1. 3. 4- thiadiazolone-(5), and 3- methyl -5- (41- methoxy)- anilino-1. 3. 4- thiadiazolone- (2). As coupling components there may be used phenols, naphthols, enols, aromatic amines, or eneamines. The oxidizing or dehydrogenating agent may be a ferric or cupric salt, ferricyanide, mercury (II) salt, cerium (IV) salt, persulphate, perborate, hypochlorite, peroxide, oxygen or air. Yellow to greenish-blue dyes are obtained. Preferred coupling components are those containing an amino group e.g. an aromatic amine, or an indole derivative such as an alkyl or arylindole. The basic diazapolymethine dyestuffs are specially suitable for dyeing polyacrylonitrile fibres. In examples, 3- methyl -5- anilino -1. 3. 4- thiadiazolone -(2)- hydrazone -5- hydrochloride is coupled with dimethyl aniline in presence of ferric chloride to form a dyestuff salt of the formula: <FORM:0858181/IV (c)/3> 2- methylmercapto -4- methyl -1. 3. 4- thiadiazo-lone -(5)-hydrazone is coupled with 3- amino-toluene in presence of ferric chloride and the dye is precipitated with a solution of zinc and sodium chlorides to form a dye salt of formula: <FORM:0858181/IV (c)/4> Many other dyestuffs of the stated general formula are specified, including those in the production of which there are used as coupling components, naphthols, naphthol sulphonates, amino phenols, toluols, phenylene diamines, diphenylamines, ethoxy diphenylamines, toluidines, cyanoethyl anilines, hydroxyethyl anilines, phenyl pyrazolones, and acetoacetanilide. Specification 857,198 is referred to.