Microwave-assisted esterification of P-acids

The possibilities for the preparation of dialky phenylphosphonates were evaluated. On the one hand, the oxidation of phenyl-H-phosphinates gave the corresponding phenylphosphonic acid monoesters. On the other hand, phenylphosphonates may be prepared by MW-assisted direct esterification of phenylphosphonic acid. The reaction with alcohols was performed under MW irradiation in the presence of an ionic liquid as the catalyst. The second ester function was established by alkylating esterification carried out with alkyl halides in the presence of triethylamine under MW conditions.