Amberlyst-15, an efficient heterogeneous catalyst for the 1,4-dihydropyridine synthesis

The paper reported synthesizing 1,4-dihydropyridine (1,4-DHP) from β-ketoester, aromatic aldehyde, and ammonium acetate via a two-step, using heterogeneous catalyst Amberlyst-15 in high yields at room temperature. The method was applied to synthesize some 1,4-DHP derivatives. Moreover, the catalyst was reused at least five times without loss of catalytic activity under eco-friendly conditions.