Abstract: The invention relates to a process which comprises reacting a compound of formula I, ##STR1## in which A.sub.1 is a radical which does not compete with the activity of the ##STR2## OR A TAUTOMER THEREOF, WITH A COMPOUND OF FORMULA II,a.sub.2 -- ch.sub.2 -- cn iiin which A.sub.2 is a radical which does not compete with the activity of the --CH.sub.2 CN group of the compound of formula II but provides the vicinal methylene group with sufficient acidity to react with the .dbd.NH group of the compound of formula I,and with sulphur,To obtain a compound of formula III, ##STR3## in which A.sub.1 and A.sub.2 are as defined above, which compounds of formula III are useful as intermediates for the production of dyestuffs.

Abstract: Disclosed are azo dyes of the formula ##STR1## wherein R.sub.1 is an aliphatic or aryl group,R.sub.2 is cyano, alkoxycarbonyl or substituted alkoxycarbonyl,R.sub.3 is an aliphatic or aryl group, andK is a coupling component radical,The synthesis thereof and the use thereof for the dyeing and printing of textile and non-textile substrates. The disclosed disperse dyes are useful for dyeing and printing synthetic and semi-synthetic, hydrophobic, high molecular weight materials such as linear aromatic polyesters, polyamides, cellulose 21/2 acetate and cellulose triacetate. The obtained dyeings have satisfactory fastness properties, particularly fastness to light, thermofixation, sublimation and pleating.