Synthetic methodology of pyrimido[4,5‐<i>b</i>]quinoline derivatives

Abstract

Abstract This review discusses the synthetic pathways of an important class of quinolines known as pyrimido[4,5‐b]quinoline. Due to their profound range as biologically active compounds, they attracted the attention of medical/organic researchers. The construction of pyrimido[4,5‐b]quinolines involved the intermolecular cyclization of diamino chloropyrimidine carbaldehyde and intramolecular cyclization of 2‐amino‐3‐cyanotetra/hexahydroquinoline, 2‐aminoquinoline‐3‐carbonitriles, ester or amide. That class of organic compounds was constructed from the reaction between 2‐chloro‐3‐formylquinoline with amidine, urea, and thiourea. Also, barbituric acid and uracil and their analogous play an important role in synthesizing pyrimidoquinolines via multicomponent reaction strategies (MCR).