Studies on the use of silica-supported ammonium hydrogen carbonate as an efficient reagent for the synthesis of 1-aminophosphonates under microwave irradiation in solvent-free conditions is reported. Investigations showed that this reaction proceeds by the formation of methanediamine as an intermediate. The reaction in the absence of diethyl phosphite gave cis-imidazolines as the major products.
1-aminophosphonates - silica - ammonium hydrogen carbonate - methanediamines - imidazolines