One-pot, solvent-free, and efficient synthesis of 2,4,6-triarylpyridines using CoCl2.6H(2)O as a recyclable catalyst

A one-pot, three components coupling of aryl aldehyde, acetophenone, and ammonium acetate was performed to afford the corresponding 2,4,6-triarylpyridines (TAP(1-17)). The TAP(1-17) were synthesized in the presence of cobalt(II) chloride hexahydrate (CoCl2.6H(2)O) via an improved Chichibabin pyridine synthesis protocol. This study has shown that CoCl2.6H(2)O promotes this reaction in comparison to other transition metal salt such as with FeCl3, NiCl2.6H(2)O, CuCl2.2H(2)O, CdCl2.H2O, SbCl3, SnCl2.2H(2)O, and ZnCl2. This method has several advantages, for example, excellent yields, short reaction times, easy work up, and solvent-free condition. Also, this catalyst was recyclable for four consecutive runs.