Synthesis and properties of heterocyclic monoazo dyes derived from 3-cyano-4-trifluoromethyl-6-substituted-2(1H)-pyridinethiones

The synthesis and properties of new heterocyclic monoazo dyes derived from polyfunctionally substituted 3-amino-4-trifluoromethyl-thieno[2,3-b]pyridines as diazo components are reported. By appropriate selection of substituents in the coupling components, dyes varying in hue from yellow to blue can be obtained. The dyes were applied to polyester; their spectral, fastness properties and colour assessment are reported.