Synthetic methodology of pyrimido[4,5‐b]quinoline derivatives

This review discusses the synthetic pathways of an important class ofquinolines known as pyrimido[4,5-b]quinoline. Due to their profound range asbiologically active compounds, they attracted the attention of medical/organicresearchers. The construction of pyrimido[4,5-b]quinolines involved theintermolecular cyclization of diamino chloropyrimidine carbaldehyde andintramolecular cyclization of 2-amino-3-cyanotetra/hexahydroquinoline,2-aminoquinoline-3-carbonitriles, ester or amide. That class of organic com-pounds was constructed from the reaction between 2-chloro-3-formylquinolinewith amidine, urea, and thiourea. Also, barbituric acid and uracil and theiranalogous play an important role in synthesizing pyrimidoquinolines viamulticomponent reaction strategies (MCR).