Sparingly water-soluble azo compounds of the formula ##STR1## wherein D is phenyl, substituted phenyl, thiazolyl, substituted thiazolyl, benzothiazolyl, substituted benzothiazolyl, 1,3,5-thiadiazolyl, phenyl-1,3,4-thiadiazolyl, nitrobenzoisothiazolyl or substituted thienyl,Wherein each substituent of substituted phenyl, substituted thiazolyl and substituted benzothiazolyl is independently chloro, bromo, nitro, cyano or methylsulfonyl and each substituent of substituted thienyl is independently nitro or acetyl,R.sub.1 is hydrogen, alkyl, alkoxy or --NH--Y--R.sub.5, wherein Y is --CO--, --COO-- or --SO.sub.2 --, and R.sub.5 is alkyl, haloalkyl, phenyl or substituted phenyl,R.sub.2 is hydrogen or alkoxy,R.sub.3 is phenoxyalkyl, substituted phenoxyalkyl, benzyloxyalkyl or substituted benzyloxyalkyl, andR.sub.4 is hydrogen, cyclohexyl, alkyl or alkyl substituted by chloro, bromo or --O--CO--NH--R.sub.6, wherein R.sub.6 is alkyl or phenyl are eminently suitable for application as disperse dyes. From aqueous dispersion such dyes build up powerfully on regenerated fibres and synthetic fibres of high molecular weight and hydrophobic character. Dyeings are obtained which are fast to thermofixation, sublimation, pleating, gas fumes, dry cleaning and wet treatments.