Synthesis, structure, and reactions of (4-aryl-3-cyano-6-oxopiperidin-2-ylidene)malononitriles

• DOI: 10.1007/s10593-016-1918-3
• Publication Date: 2016-08-31T00:34:22Z
• Authors: Victor V. Dotsenko; Arif I. Ismiev; Anastasiya N. Khr...; Konstantin A. Frolov; Sergey G. Krivoko...; Elena A. Chigorina; Aleksey P. Snizhko; Vladimir M. Gromenko; Ivan S. Bushmarinov; Rizvan K. Askerov; Tatyana M. Pekhte...; Sergey Yu. Suykov; Elena S. Papayanina; Aleksandr V. Mazepa; Abel M. Magerramov
• Keywords: Triethylamine; Thioglycolic acid

The reaction of aromatic aldehydes with Meldrum's acid and malononitrile dimer in the presence of triethylamine led to the formation of (4-aryl-3-cyano-6-oxo-1,4,5,6-tetrahydropyridin-2-yl)malononitrile triethylammonium salts, which were converted upon acidification to (4-aryl-3-cyano-6-oxopiperidin-2-ylidene)malononitriles. The reaction of these compounds with thioglycolic acid anilide was observed to produce derivatives of 1,6-naphthyridine or thieno[2,3-h][1,6]naphthyridine, depending on the conditions. Structures of (3-cyano-6-oxo-4-phenylpiperidin-2-ylidene)malononitrile and its triethylammonium salt were studied by X-ray structural analysis.