Disazo compounds of the formula ##STR1## and salt thereof, D is the radical of a diazo component of the benzene or naphthalene series.K is the radical of a heterocyclic coupling component of the aminopyrazole-, pyridone- or barbituric acid-series, n is 1 to 4,R.sub.1 is hydrogen, C.sub.1-4 alkyl or substituted C.sub.1-4 alkyl,each of R.sub.2 and R.sub.3 is independently hydrogen, halo, C.sub.1-4 alkyl, substituted C.sub.1-4 alkyl, C.sub.1-4 alkoxy, substituted C.sub.1-4 alkoxy, --NHCO--Rhd 5, amino, substituted amino or a quaternary ammonium group, wherein R.sub.5 is C.sub.1-4 alkyl, substituted C.sub.1-4 alkyl, C.sub.1-4 alkoxy or amino,R.sub.4 is hydrogen, C.sub.1-4 alkyl, C.sub.1-4 alkoxy, halo or nitro,X is a bridging radical, and with the proviso that the number of anionic groups equals or exceeds the total number of basic and cationic groups,are useful as direct dyes, as such or in the form or solid or particularly liquid aqueous dye preparations, for dyeing or printing hydroxy group- or nitrogen- containing organic substrates, such as textiles consisting of or containing cellulose material, leather, glass and especially paper, and are also useful in inks.