Collect. Czech. Chem. Commun. 1985, 50, 1962-1970

Synthesis of 3,5-dicyano-4-phenyl-2,6-bis(4-p-terphenylyl)-1,4-dihydropyridine. An attempt at extending the Hantzsch synthesis

Štefan Marchalín and Josef Kuthan

Department of Organic Chemistry, Prague Institute of Chemical Technology, 166 28 Prague 6


The 3-oxopropanenitrile IIIc, prepared from 4-acetyl-p-terphenyl (IV) by the sequence IVVVIIIIc, reacts with benzaldehyde and ammonium acetate in acetic acid to give the Hantzsch 1,4-dihydropyridine VIIc and the corresponding pyridine derivative VIIIc. The alternative cyclocondensation of benzylidene derivative IIc and 3-oxopropanenitrile IIIc in the presence of ammonium acetate exclusively gives the pyridine derivative VIIIc. Rate of thermal and oxidative aromatizations of the 1,4-dihydropyridine derivatives, VIIaVIIcVIIIaVIIIc, decreases in the order VIIc > VIIb > VIIa. Mechanism of these transformations and spectral characteristics of compounds VIIc and VIIIc are discussed with regard to their molecular structure.