Multicomponent Reactions of Acetoacetanilide Derivatives with Aromatic Aldehydes and Cyanomethylene Reagents to Produce 4H-Pyran and 1,4-Dihydropyridine Derivatives with Antitumor Activities

The multi-component reaction of either acetoacetanilide derivative 1a or b with any of the aldehyde derivatives 2a-d and malononitrile 3 in the presence of triethylamine as a catalyst gave the 4H-pyran derivatives 4a-g, respectively. Carrying the same reaction but using a catalytic amount of ammonium acetate gave the 1,4-dihydropyridine derivatives 5a-f, respectively. The use of ethyl cyanoacetate instead of malononitrile in the presence of a catalytic amount of triethylamine gave the 4H-pyran derivatives 7a-d, respectively. Compound 4e was used to synthesize 1,4-dihydropyridine 9a-c and arylhydraone 11a-e derivatives were synthesized from 4a and e. The anti-tumor evaluations of the newly synthesized products were tested against six human cancer and normal cell lines. The results showed that compounds 4a, b, f, 5d, f, 9 and 11a-d had optimal cytotoxic effect against cancer cell lines with IC50 < 550 nM. The toxicity of the most active compounds was further measured against shrimp larvae.