GB814391A - New stilbene monoazo-dyestuffs and process for their manufacture - Google Patents

Abstract

The invention comprises dyestuffs of formula <FORM:0814391/IV (c)/1> where R1 is a benzene residue, R2 is a naphthalene residue fused to the triazole in the 1,2-positions and R3 is an acetoacetylaminobenzene residue free from groups imparting solubility in water, the groups -NHCO-and N2 being in p-position to each other. They may be made by coupling appropriately substituted diazotized anilines with the required acetoacetylaminobenzenes. An indirect method of diazotization is preferred. The aniline starting derivatives are made by acylating compounds of formula <FORM:0814391/IV (c)/2> to introduce the group OC-R1-NO2 with subsequent reduction of the nitro group. The stilbene amines are made by coupling, advantageously in an acid medium, a diazotized 4-nitro - 41 - aminostilbene - 2,21 - disulphonic acid with a naphthylamine which couples in a vicinal position to the amino group, oxidizing, e.g. with copper-tetramine solutions, the o-amino-azo-group to yield a triazole and subsequently reducing the nitro group. Naphthylamine mono- and di-sulphonic acids are mentioned, specified being 1-naphthylamine-4 or -5-mono- and -5,7-di-sulphonic acids and 2-naphthylamine-6 and -7-mono- and -3,5, -3,6 and -5,7-di-sulphonic acids. Specified acylating agents are 4-nitro- and 3-methyl- and -chloro-4-nitro-benzoyl chlorides. The acetoacetylaminobenzenes advantageously contain a further substituent in the benzene ring attached to the NH group. Methyl, ethyl, methoxy ethoxy, bromine, chlorine and acetylamino substituents are specified, methoxy and ethoxy groups being preferred. Specified coupling components are acetoacetylaminobenzene, 1-acetoacetylamino-2-and -4-methoxy-, 2-methoxy - 5 - methyl -, - 2,4 - dimethyl -, -2,5 - dimethoxy -, 2 - methoxy - and - ethoxy - 4 - chloro - and - bromo - 5 - methyl - and - 5-methoxy - 4 - acetylamino - 2 - chloro - benzenes. The dyestuffs dye or print animal fibres such a wool, silk and leather but are especially suitable on cellulosic fibres such as cotton, linen, artificial silk and regenerated cellulose. Greenish yellow tints are obtained. In examples illustrating the preparation of the dyes and their use in dyeing processes reactants used are chosen from those given above with the addition of 1-acetoacetylamino-2,5-dimethoxy-4-chloro-benzene. Specification 659,130 is referred to.