Synthesis and Cytotoxic Activity of a New Family of α-Hydroxyphosphonates with the Benzothiophene Scaffold

α-Hydroxyphosphonates the most prominent class within phosphonates remain of utmost importance because of their potential and real biological activity as pharmaceutical or pesticide agenst that is the consequence of their enzyme inhibitory properties. After optimizing the synthesis, 23 members of a new family, α-hydroxy-α-(benzothiophen-2-yl)-methylphosphonates were synthesized by the Pudovik reaction of benzo[b]thiophene-2-carboxaldehydes and diethyl phosphite performed at 26 °C in the presence of triethylamine as the catalyst. One of the products was also characterized by single-crystal X-ray analysis. The cytotoxic effect of the α-hydroxy-α-benzothiophenyl-methylphosphonates was tested on U266 myeloma, A2058 melanoma, HT-29 colon and EBC-1 lung cancer cell lines. Most of the molecules showed significant activity; the greatest effects were seen after treatment with hydroxyphosphonates with a trifluoromethyl group in the benzene ring.