Synthesis of 2-amino-4-phenyl-6-(phenylsulfanyl)-3,5-dicyanopyridines by tandem reaction

A novel basic ionic liquid, 1-(2-aminoethyl)pyridinium hydroxide, containing both Bronsted base and Lewis base sites has been used as an efficient catalyst for the synthesis of 2-amino-4-phenyl-6-(phenylsulfanyl)-3,5-dicyanopyridines. The condensation and oxidation tandem reaction of aldehydes, malononitrile, and thiols, performed in aqueous ethanol, afforded reasonable to good yields within 30–60 min. After the reaction, the catalyst could be recycled and reused. A possible mechanism to account for the tandem reaction is proposed. .