1, 4-Dihydroxy-9, 10-anthraquinone monoimine and differently substituted derivatives thereof (6a-i) have been prepared by ammonolysis of the corresponding 1, 4-dihydroxy-9, 10-anthraquinones. 1H-and 13C-nmr studies show the existence of a rapid tautomeric equilibrium in quinone imines of type 6. Diels-Alder reaction with the 1, 4-anthraquinonoid tautomer of quinone monoimines 6a, e affords ABCD tetracyclic systems related to those ...
