A DOMINO REACTION FOR THE SYNTHESIS OF 2 H -PYRANO[4'',3'',2'':4',5']CHROMENO[2',3':4,5]THIENO[2,3- b ]PYRIDIN-2-ONES
2-{[(5-Hydroxy-2-oxo-2 H -chromen-4-yl)methyl]sulfanyl}pyridine-3-carbonitrile derivatives were synthesized in a reaction of 4-chloromethyl-5-hydroxycoumarin with substituted 2-thioxopyridine-3-carbonitriles. The presence in the molecule of spatially adjacent active methylene, nitrile, and hydroxyl groups under the action of a base leads to consecutive intramolecular cyclization reactions with the formation of a novel heterocyclic system pyrano[4'',3'',2'':4',5']chromeno[2',3':4,5]thieno[2,3-b]pyridine. Authors: Svitlana P. Bondarenko, Igor V. Zhytnetskyi, Serhii V. Semenov, Mykhaylo S. Frasinyuk*