Green synthesis and cytotoxic activity of dibenzyl α-hydroxyphosphonates and α-hydroxyphosphonic acids

A series of dibenzyl α-hydroxyphosphonates and the corresponding α-hydroxyphosphonic acids, mostly new compounds, have been synthesized. The dibenzyl α-hydroxyphosphonates have been obtained in the Pudovik reaction of substituted benzaldehydes and dibenzyl phosphite in the presence of triethylamine as the catalyst. The amount of the solvent was minimized during the reaction, and the workup involved crystallization from the reaction mixture. A new protocol was developed to transform the dibenzyl 1-hydroxyphosphonates to the corresponding phosphonic acids by catalytic hydrogenation. The derivatives prepared were screened as potential cytotoxic agents against Mes-Sa human uterine sarcoma cell line.