AN UNUSUAL RESULT OF THE REACTION OF α-ACETYLENE ALDEHYDES, PYRIDINES, AND MALONIC ACID. SYNTHESIS AND STRUCTURE OF NOVEL PYRIDINE BETAINES

5-Aryl-2-carboxy-5-(pyridin-1-ium-1-yl)penta-2,4-dienoates, previously unknown pyridine betaines, were formed in 32–70% yields as a result of the reaction of arylpropynals, substituted pyridines, and malonic acid instead of the expected 5-arylpent-2-en-4-ynoic acids. The molecular structure of the novel compounds was studied by X-ray structural analysis. Authors: Aleksander А. Golovanov*, Sergei А. Dan'kov, Sergey А. Sokov, Pavel А. Melnikov, Anton I. Ukolov, Evgeniya D. Voronova, Anna V. Vologzhanina, Aleksander S. Bunev