DISAZO COMPOUNDS AND THEIR USE AS DYESTUFFS

Compounds of the formula in which R1 is hydrogen or methyl, either R2 is hydrogen; C1-6alkyl; C1-4alkyl monosubstituted by halo or phenyl; C2-4alkyl monosubstituted in the 2-, 3- or 4-position by hydroxy or C1-2alkoxy; C5-7cycloalkyl; C5-7cycloalkyl substituted by one to three C1-4alkyl groups; phenyl; phenyl substituted by one or two substituents selected from the group consisting of halo, C1-4alkyl and C1-4alkoxy; or -CH2CH2SO3H, and R3 is hydrogen or C1-6alkyl, or R2 and R3, together with the nitrogen atom to which they are bound, form a 5- or 6-membered saturated heterocyclic ring, and mixtures thereof, which compounds are in free acid or salt form, useful for dyeing and printing hydroxy group-containing and amido group-containing organic substrates such as natural and synthetic polyamides (e.g., wool, silk and nylon) and natural and regenerated cellulose (e.g., cotton, viscose and spun rayon).