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.

Synthesis of (E)-2-amino-N'-benzylidenehexahydroquinoline-3-carbohydrazide.

A one-pot, multi-component protocol for the synthesis of a new class of functionalized quinoline carbohydrazide derivatives via reaction of various anilines, dimedone, aromatic aldehydes, and cyanoacetohydrazide is described. The reactions are completed in the presence of catalytic amount of piperidine, respectively, in melt conditions and then in ethanol/water (1:1) as green solvent at 80 °C. Mild conditions, green medium, short reaction times, simple workup and purification process with no chromatographic technique, and good yields are the main advantages of this method.