The present invention relates to disperse azo dyes of formula ##STR00001##
wherein R.sub.1 is bromo, nitro, cyano, methyl, methoxy or trifluoromethyl; R.sub.2 is hydrogen, chloro, bromo or trifluoromethyl; R.sub.3 is hydrogen, chloro, bromo, methoxy, trifluoromethyl, nitro or cyano; and R.sub.4 is methyl, ethyl, n-propyl, 2-methoxyethyl, methoxycarbonylmethyl or 2-methoxycarbonylethyl;
with the proviso that R.sub.1 is cyano in case R.sub.2 denotes chloro or bromo,
to a process for the preparation of such dyes and to their use in the dyeing or printing of semi-synthetic and, especially, synthetic hydrophobic fibre materials, more especially textile materials.

The present invention relates to disperse azo dyes of formula

##STR00001##

wherein

R.sub.1 is bromo, nitro, cyano, methyl, methoxy or trifluoromethyl;

R.sub.2 is hydrogen, chloro, bromo or trifluoromethyl;

R.sub.3 is hydrogen, chloro, bromo, methoxy, trifluoromethyl, nitro or cyano; and

R.sub.4 is methyl, ethyl, n-propyl, 2-methoxyethyl, methoxycarbonylmethyl or 2-methoxycarbonylethyl;

with the proviso that R.sub.1 is cyano in case R.sub.2 denotes chloro or bromo,

to a process for the preparation of such dyes and to their use in the dyeing or printing of semi-synthetic and, especially, synthetic hydrophobic fibre materials, more especially textile materials.

A compound of formula ##STR00001##
wherein V, W, X and Y represent N or CH, at least one of V, W, X and Y being N and at least two of V, W, X and Y being CH; R.sub.1, R.sub.2 and R.sub.3 are each independently of the other hydrogen, C.sub.1-C.sub.8 alkyl, C.sub.1-C.sub.8 alkoxy, nitro, cyano, trifluoromethyl, halogen or hydroxy; and the compound provides good lightfastness properties to textile fibre materials, in particular PES fibre materials.