GB313293A - Process for the manufacture of new basic azodyestuffs - Google Patents

Abstract

313,293. Carpmael, A., (I. G. Farbenindustrie Akt.-Ges.). May 23, 1928. Azo dyes containing a quaternary group are made (1) by coupling a diazotized unsulphonated amino-arylene thiazol compound of the formula :- in which X = an alkyl or aryl residue and in which the amino group may be attached either to the arylene residue when X is alkyl or to X, when X is an aryl residue, with an unsulphonated azo-component, and treating the azo-compound thus formed with an alyklating agent of the formula: alkyl-O-SO2-Y in which Y is aryl or O-alkyl or (2) the acylated aminothiazol compound is first alkylated and the quaternary base thus formed is diazotized and coupled with an unsulphonated azo component; the acyl group is then removed by hydrolysis. It is assumed that the quaternary group is formed at the nitrogen atom in the thiazolic ring. The following examples are specified. (1) The dye dehydrothio-p-toluidine # #-naphthol is treated with dimethylsulphate or p-toluenesulphonic acid methvl ester in chlorobenzene solution. The product dyes are mordanted cotton yellowish red. A bluish red is obtained starting from dehydrothio-p-xylidene # #-naphthol. (2) Acetyldehydrothio-p-toluidine is treated with dimethylsulphate in chlorobenzene and the hydrolyzed quaternary compound diazotized and coupled with #-naphthol, 1-phenyl-3-methyl-5-pyrazolone, resorcinol, 2 : 7-dioxynaphthalene, a-naphthylamine or ethyl - # - naphthylamine. If m-amino-p-cresolmethylether is used the resulting amino-azo dye may be diazotized and coupled with resorcinol or m-toluylenediamine. (3) The dyestuff dehydrothio-p-toluidine --> 1-phenyl-3-methyl - 5 - pyrazolone is treated with dimethylsulphate with or without chlorobenzene as solvent. (4) The dyestuffs dehydrothio - p - toluidine # acetoacetic acid anilide or o-toluidide, methylketol or acetyl acetone are treated in chlorobenzene with dimethylsulphate. (5) The dyestuff 6-amino-2- methylbenzthiazol # 1-phenyl-3-methyl-5-pyrazolone is treated as in (4). The same product is obtained by alkylating 6-acetamino-2-methylbenzthiazol with dimethylsulphate, hydrolyzing. diazotizing and coupling with 1-phenyl-3-methyl- 5-pyrazoline. 6-Amino-2-methlbenzothiazol is obtained by allowing disulphur dichloride to act on p-aminoacetanilide (Specification 17417/14), treating with alkali to from the o-aminomercaptan which is converted to the aminothiazole by acetic anhydride and hydrolysis.