Two routes of heterocyclization of 2-alkynylanthraquinone-1-diazonium salts. The synthesis of 1H-naphtho[2,3-h]cinnoline-4,7,12-trione

The possibility of the heterocyclization of vic-alkynylanthraquinonediazonium salts with the formation of a 5- or 6-membered ring, depending on the reaction conditions, is established. The heterocyclization of 2-alkynyl-9,10-anthraquinone-1-diazonium salts to form 1H-naphtho[2,3-h]cinnoline-4,7,12-triones is reported.