Disperse dyes: nitro-thiophene azo dyes for bright blue shades on polyester

摘要

A disperse monoazo dye of the formula: ##STR1## wherein each of R and R.sup.3 represents a lower alkyl radical, R.sup.1 represents a lower alkyl or C.sub.3 -C.sub.6 alkenyl radical andPPR. sup.2 represents a C.sub.2 -C.sub.6 alkyl radical carrying a hydroxy or acyloxy substituent.