The use of 4-R1-benzylidene-4-phenylbenzoylacetonitriles for synthesis of unsymmetrically substituted 3,5-dicyano-1,4-dihydropyridines and 2-amino-4H-pyrans

Abstract

3,5-Dicyano-1,4-dihydropyridine derivatives III-V have been prepared by cyclocondensation of benzylidene-4-phenylbenzoylacetonitrile (Ia) with the enamines IIa-IIc. 2-(4-Biphenylyl)-4-(4-R1-phenyl)-6-methyl-3,5-dicyano-1,4-dihydropyridines VI-VIII are formed by condensation of ketonitriles Ib-Id with 3-amino-2-butenenitrile (IIa). Base-catalyzed reaction of compound Ia with enaminonitrile IIa gives the adduct IX which, on dehydration, forms 1,4-dihydropyridine III. 4H-Pyrans X and XI have been prepared by cyclocondensation of the ketonitrile Ia with propanedinitrile and methyl cyanoacetate, respectively.