New intermediates and dyestuffs for synthetic fibres. Part VI. 1-Arylaminoanthraquinones

The synthesis of a series of 1-arylaminoanthraquinones and 2-substituted 1-anilinoanthraquinones is described; principal factors influencing the colour of the dyes are discussed, together with u.v. and i.r. data. Condensation of 1-chloroanthraquinone with 4-aminopyridine gives rise to 1-hydroxyanthraquinone and 1-aminoanthraquinone in addition to the anticipated 1-(4-pyridylamino)anthraquinone. Data obtained indicate the stabilisation of the dyes by strong hydrogen-bonding, a factor compatible with the high fastness to light shown by these dyes on synthetic fibres.