GB864742A - Improvements in or relating to acid monoazo dyestuffs of the benzene-azo-naphthaleneseries - Google Patents

Abstract

The invention comprises dyestuffs of formula: <FORM:0864742/IV(c)/1> wherein R is an aryl or aryloxy radical which may be substituted with non-water-solubilizing groups, or an <FORM:0864742/IV(c)/2> group in which R1 is hydrogen, cyclohexyl or alkyl which may be substituted and R2 is either alkyl, aralkyl, cycloalkyl or aryl which may be substituted, or together with -N= and R1 a saturated heterocyclic radical; R3 is hydrogen or a phenyl radical having in ortho-position to the -NH- group two alkyl radicals each containing not more than 4 carbon atoms and, if desired, further non-water-solubizing groups; and R4 is a hydroxy group when R3 is phenyl, or, when R3 is hydrogen, an <FORM:0864742/IV(c)/3> group wherein R5 is as R1 above and R6 is as R2, with the proviso that R, R5 and R6 are so chosen that, when R contains 4 to 16 carbon atoms the total number of carbon atoms in R5 and R6 is up to 4 and conversely that, when R contains up to 4 carbon atoms, the total number of carbon atoms in R5 and R6 is 4 to 12. The dyes are prepared in known manner by coupling an appropriately substituted diazotized orthanilic acid with a suitable aminonaphthol-sulphonic acid orsulphonamide. The dyes give red to bordeaux shades on wool, silk, leather and synthetic polyamides. A large number of the dyestuffs are specified in examples.