Table 5.

Synthesis of hybrid pyridines with indole and sulfonate moieties by using Fe₃O₄@SiO₂@urea-riched ligand /Ch-Cl^a.

^aReaction conditions: 4-acetylphenyl 4-methylbenzenesulfonate (1 mmol, 0.290 g) or 3-acetyl indole (1 mmol, 0.1590) malononitrile (1 mmol, 0.066 g) or 3-(1H-indol-3-yl)-3-oxopropanenitrile (1 mmol, 0.184 g), ammonium format (1.5 mmol, 0.094 g), benzaldehyde (1 mmol, 0.106 g), catalyst (10 mg), solvent-free, 110 °C.