Silica-Bonded 2-Hydroxyethylammonium Acetate as an Efficient and Recyclable Catalyst for the Synthesis of 2-Amino-4H-chromen-4-yl Phosphonates and β-Phosphonomalonates

Silica-bonded 2-hydroxyethylammonium acetate was synthesized easily by the reaction of 3-chloropropylsilica with ethanolamine followed by ion exchange with acetate. It was used as a heterogeneous, re-usable, efficient and easy to handle catalyst for the one-pot synthesis of a variety of 2-Amino-4H-chromen-4-yl phosphonates and beta-phosphonomalonates at room temperature under solvent-free conditions.