Cyclocondensation of α-oxoketene n,s-acetals with β-lithioamino-β-substituted acrylonitriles: a facile route to 2,6-substituted 4-amino-3-cyanopyridines

Abstract

A novel synthesis of a variety of 2,6-substituted and 3-cyano-4-dialkylamino-2,6-diheteroarylpyridines (4-dialkylamino≡pyrrolidin-1-yl, piperidino, morpholino, diethylamino and N-methylanilino; 6-heteroaryl≡phenyl, anisyl, 2-thienyl; 2-heteroaryl≡methyl, phenyl, 2-furyl and 2-thienyl) has been developed by the reaction of α-oxoketene N,S-acetals 1 with β-substituted β-lithioaminoacrylonitriles 2, generated in situ by either self condensation of lithioacetonitrile or by its reaction with substituted acetonitriles.