Search Results (2)

Background: It is known that the α-hydroxyphosphonates and their derivatives may have potential biological activity. Methods: Within the prominent class of α-hydroxyphosphonates, α-hydroxy-alkylphosphonates and their derivatives were prepared as new representatives in the hope of obtaining biologically active species. During our work the Pudovik reaction, acylation and phosphinoylation/phosphorylation methods were used. The new compounds were characterized by NMR and MS spectroscopy. The antiproliferative effects were tested on U266 (myeloma multiplex) and A2058 (melanoma) cells. Results: Ethyl methyl ketone–dialkyl phosphite and secondary phosphine oxide adducts were synthesized by the Pudovik reaction on the earlier analogy of acetaldehyde– and acetone adducts. The hydroxyphosphonates and hydroxyphosphine oxides were acylated and phosphinoylated/phosphorylated. Due to the steric hindrance in the case of the preparation of the acetone–and ethyl methyl ketone–diethyl phosphite adducts, a two-step procedure was elaborated that was also suitable for the thiophosphinoylation of the adducts. A part of the α-hydroxyphosphonates could be successfully methanesulfonylated. The new derivatives prepared were tested on myeloma and melanoma cells, and it was found that the antiproliferative activity is primarily driven by phosphinoylation, particularly by diphenylthiophosphinoylation. The most promising compound, the diphenylthiophosphinoylated hydroxyphosphine oxide, reduced the viability of the U266 cells to less than 20% after a treatment with 100 µM concentration in a long-term experiment. Conclusions: A subset of the synthesized α-hydroxyphosphonate derivatives exhibited cytotoxic activity, supporting further structural optimization to identify compounds with enhanced biological efficacy. Full article

A series of α-hydroxy-alkylphosphonates and α-hydroxy-alkylphosphine oxides were synthesized by the Pudovik reaction of acetaldehyde and acetone with dialkyl phosphites or diarylphosphine oxides. The additions were performed in three different ways: in liquid phase using triethylamine as the catalyst (1), on the surface of Al₂O₃/KF solid catalyst (2), or by a MW-assisted Na₂CO₃-catalyzed procedure (3). In most of the cases, our methods were more efficient and more robust than those applied in the literature. Two of the α-hydroxy-alkylphosphonates were subjected to single-crystal X-ray analysis, suggesting a dimeric and a chain supramolecular buildup in their respective crystals. Four α-hydroxy-alkylphosphonates and one α-hydroxy-ethylphosphine oxide were reacted with different acid chlorides to afford ten α-acyloxyphosphonates. Diethyl α-hydroxy-ethylphosphonate was transformed to the methanesulfonyloxy derivative that was useful in the Michaelis–Arbuzov reaction with triethyl phosphite and ethyl diphenylphosphinite to afford tetraethyl ethylidenebisphosphonate and diethyl α-(diphenylphosphinoyl)-ethylphosphonate, respectively. The α-hydroxyphosphonates and α-hydroxyphosphine oxides prepared were subjected to bioactivity studies, and the compounds tested exhibited limited cytotoxic effects on U266 cells with modest reductions in viability at a concentration of 100 μM. Full article