Unexpected cascade transformations in the reaction of aromatic aldehydes with the malononitrile dimer

Abstract

The one-pot reaction of aromatic aldehydes, malononitrile dimer, and triethylamine unexpectedly led to ammonium salts of not previously assumed 5,7-diamino-4-aryl-2-(dicyanomethyl)-1,4-dihydro-1,8-naphthyridine-3,6-dicarbonitriles, but the isomeric 5,7-diamino-4-aryl-2-(dicyanomethyl)-1,4-dihydro-1,6-naphthyridine-3,8-dicarbonitriles. Following neutralization and dehydrogenation led to the new, annulated with pyridine ring tricyanopyridines (TCPy).

Graphical Abstract

Keywords:

• Cascade reaction
• malononitrile dimer
• pyridines
• TCPy

Additional information

Funding

The research was performed under the financial support of the Russian Science Foundation [grant no. 17-13-01237].