Search Results (3)

Background: Methylenebisphosphonic derivatives including hydroxy-methylenebisphosphonic species may be of potential biological activity, and a part of them is used in the treatment of bone diseases. Methods: Methylenebisphosphonates may be obtained by the Michaelis–Arbuzov reaction of suitably α-substituted methylphosphonates and trialkyl phosphites or phosphinous esters, while the hydroxy-methylene variations are prepared by the Pudovik reaction of α-oxophosphonates and different >P(O)H reagents, such as diethyl phosphite and diarylphosphine oxides. Results: After converting α-hydroxy-benzylphosphonates and -phosphine oxides to the α-halogeno- and α-sulfonyloxy derivatives, they were utilized in the Michaelis–Arbuzov reaction with trialkyl phosphites and ethyl diphenylphosphinite to afford the corresponding bisphosphonate, bis(phosphine oxide) and phosphonate–phosphine oxide derivatives. The Pudovik approach led to α-hydroxy-methylenebisphosphonic species and to their rearranged products. A part of the derivatives revealed a significant cytotoxic effect on pancreatic adenocarcinoma or multiple myeloma cells. Conclusions: The new families of compounds synthesized by our novel approaches may be of practical importance due to the significant cytotoxic activity on the cell cultures investigated. Compounds lacking hydroxy groups showed anti-myeloma activity or limited effect on pancreatic cancer (PANC-1) cells unless substituted with para-trifluoromethyl group. Hydroxy-containing bisphosphonates and their rearranged derivatives demonstrated varying effects depending on structural modifications. While myeloma (U266) cells indicated greater sensitivity overall, the most significant reductions in cell viability were observed in PANC-1 cancer cells, raising potential therapeutic applications of bisphosphonates beyond myeloma-associated bone disease, particularly for malignancies like pancreatic ductal adenocarcinoma. Full article

New hydroxy-methylenebisphosphonic derivatives were prepared with different P-functions. The outcome of the reaction of α-oxophosphonates (YC(O)P(O)(OR)₂) and dialkyl phosphites or diarylphosphine oxides depended on the Y substituent of the oxo-compound, the nature of the P-reagent and the amount of the diethylamine catalyst. Starting from dimethyl α-oxoethylphosphonate, in the presence of 5% of diethylamine, the corresponding Pudovik adduct was the single product. While using 40% of the catalyst, the rearranged species with the >P(O)–O–CH–P(O)< skeleton was the exclusive component. A similar reaction of α-oxobenzylphosphonate followed the rearrangement protocol. X-ray crystallography revealed not only the spatial structures of the three products, but also an intricate pattern evolving from the interplay of slight chemical differences, solvent inclusion and disorder as well as H-bridge patterns, which invite further investigation. In vitro activity of the compounds was assessed on different tumor cell cultures using end-point-type cell tetrazolium-based measurements. These structure–activity studies revealed a cytostatic effect for four rearranged derivatives containing aromatic units. One of them had a pronounced effect on MDA-MB 231 and Ebc-1 cells, showing IC₅₀ = 37.8 and 25.9 µM, respectively. Full article

The reaction of diethyl α-oxoethylphosphonate and diethyl oxobenzylphosphonate with diethyl phosphite, dimethyl phosphite, and diphenylphosphine oxide affords, depending on the substrates and conditions (nature and quantity of the amine catalyst, temperature, and solvent), the Pudovik adduct and/or the corresponding >P(O)–CH–O–P(O)< product formed by rearrangement. The nature of the substituent on the central carbon atom (a methyl or phenyl group) influences the inclination for the rearrangement. The asymmetric products (either adducts or rearranged species) with different P(O)Y functions (Y = RO or Ph) exhibit interesting NMR features. Full article