Three-Component Cyclization of Phenyl 1,3-Dicarbonyls with α,β-Enaldehydes and 2-(Aminomethyl)aniline to Pyrido[2,1-b]quinazolines

Abstract

The three-component condensation of phenyl-substituted 1,3-dicarbonyl compounds, α,β-un­saturated aldehydes, and 2-(aminomethyl)aniline under mild conditions resulted in regio- and chemoselective formation of tetrahydro-7H-pyrido[2,1-b]quinazoline derivatives as mixtures of trans and cis diastereomers, most of which were isolated as individual isomers. Their steric structure was determined by ¹H and ¹³C NMR spectroscopy, including two-dimensional ¹H–¹³C HSQC/HMBC and ¹H–¹H NOESY experiments, as well as by X-ray analysis.