One-pot multi-component synthesis of new bis-pyridopyrimidine and bis-pyrimidoquinolone derivatives.

A variety of bis-heterocycles such as bis(pyrimido[4,5-]quinolone), bis(chromeno[3',4':5,6]pyrido[2,3-]pyrimidine), bis(pyrido[2,3-:6,5-]dipyrimidine), and bis(benzo[]pyrimido[4,5-]quinolone) derivatives were synthesized one-pot, multi-component reaction of various 6-aminouracils or 6-aminothiouracils, terephthalaldehyde, and CH-acids such as 4-hydroxycoumarin, dimedone, 2-hydroxy-1,4-naphthoquinone, barbituric acid, and thiobarbituric acid in EtOH as a solvent at reflux. The mild conditions, fast rate of reaction, absence of catalyst, different functional group compatibility, simple operation and work-up involving no chromatographic process, are worth mentioning.