C07C 309/54

Sulfonic acids having sulfo groups bound to carbon atoms of six-membered aromatic rings of a carbon skeleton containing nitrogen atoms, not being part of nitro or nitroso groups, bound to the carbon skeleton the carbon skeleton being further substituted by doubly-bound oxygen atoms the carbon skeleton containing carbon atoms of quinone rings at least one of the nitrogen atoms being part of any of the groups , X being a hetero atom, Y being any atom