Synthesis of Pyrimido[4, 5-b]quinolones from 6-Aminopyrimidin-4- (thi)one Derivatives (Part I)

Quinoline and pyrimidine are well-known moieties, which appear in various natural and synthetic products. Furthermore, quinoline-pyrimidine-inspired hybrids are known to have several biological properties. In addition, many pyrimido[4,5-b]quinolinone ring systems, specifically concerning medicinal chemistry, have been reported over the past decade. This review depicts the synthesis of pyrimido[4, 5-b] quinolones (PyQs4,5-b) through 6-aminopyrimidin-4-(thi)one derivatives. The preparation of PyQs4,5-b was clarified through the following chemical reactions: Vilsmeier-Haack formylation, Hantzsch-like reaction, and one-pot three-component reaction.