Formation of Csp 2 -N bond under metal-catalyst-free conditions for the synthesis of pyridopyrazoloquinazoline derivatives

Abstract

A series of pyrido[2′,3′:3,4]pyrazolo[5,1-b]quinazolin-10(12H)-one derivatives were obtained by a reaction of 2-aminobenzohydrazides and 2-chloropyridine-3-carbaldehydes catalyzed by iodine in the presence of Cs₂CO₃. A feature of the procedure is the formation of Csp²-N bond under metal-catalyst-free conditions.