3-Cyano-1,2,4-thiadiazolyl-5-czo dyestuffs

An azo dyestuff, free from sulphonic acid groups, of the formula ##STR43## wherein d and c are independently hydrogen, chloro, bromo, lower alkyl, lower alkoxy, lower alkylmercapto, phenyl, phenoxy, phenylmercapto, cyclohexyl, cyclohexylmethyl, benzyl, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl;

• and
• c is additionally trifluoromethyl or acylamino wherein the amino group is otherwise unsubstituted or substituted by methyl, and acyl is alkanoyl of up to 5 carbon atoms, alkylcarbamyl of up to 5 carbon atoms, alkoxycarbonyl of up to 5 carbon atoms, phenylcarbamyl, phenoxycarbonyl, benzoyl, phenoxyacetyl, chloroacetyl or phenylacetyl;
• and
• R.sub.1 and R.sub.2 are independently hydrogen or lower alkyl which is unsubstituted or substituted by:
• fluoro, chloro, bromo, phenyl, lower alkoxy, lower alkylcarbonyloxy, lower alkylcarbonylamino, benzoyloxy, benzoylamino (chloro-, bromo-, methyl-, ethyl-, methoxy- or ethoxy-) benzoylamino, cyano, hydroxy, phenoxy, phenylcarbonyl, phenylsulphonyloxy, phenoxycarbonyl, phenylthio, (chloro-, bromo-, methyl-, ethyl-, methoxy- or ethoxy) phenoxy, (chloro-, bromo-, methyl-, ethyl-, methoxy-, or ethoxy-) phenylcarbonyl, (chloro-, bromo-, methyl-, ethyl-, methoxy-, or ethoxy-) phenylsulphonyloxy, (chloro-, bromo-, methyl-, ethyl-, methoxy-, or ethoxy-) phenoxycarbonyl, (chloro-, bromo-, methyl-, ethyl-, methoxy-, or ethoxy-) phenylthio, lower alkylsulphonyl, lower alkoxycarbonyloxy, phenoxycarbonyloxy, phenylaminocarbonyloxy, aminocarbonyl, mono-lower alkylaminocarbonyl di-lower alkylaminocarbonyl, lower alkylcarbonyl, succinimido, phthalimido, lower alkoxycarbonyl cinnamoyl, thiophenecarbonyl, pyridinecarbonyl, phenoxyalkylcarbonyloxy, phenylaminoalkylcarbonyloxy or (lower alkoxy- or phenoxy-) carbonylalkylcarbonyl (-oxy or -amino).