Preparation of new benzochromene derivatives using triethylamine, 2-hydroxyethylammonium formate, and Fe3O4@SiO2@[O-(CH2)2-NH2][HCO2H] as catalysts

In this research, the preparation of new benzochromene derivatives was synthesized in a three-component reaction using 1-naphthol and 2-naphthol, methylsulfonylacetonitrile and malononitrile, and aldehyde derivatives in the presence of triethylamine as catalyst, 2-hydroxyethylammonium formate as ionic liquid catalyst, and Fe₃O₄@SiO₂@[O-(CH₂)₂-NH₂][HCO₂H] as nanocatalyst. The advantages of this protocol include high yields, green chemistry, short reaction times, and catalyst recycling.