Modranka, JakubJakubowski, RafałJanecki, Tomasz2016-02-092016-02-092014Synlett, Vol. 25, Issue 1, pages 105-109http://hdl.handle.net/11652/1151https://www.thieme-connect.com/products/ejournals/abstract/10.1055/s-0033-1340071A new, versatile method for the synthesis of, so far unknown, variously substituted 4-methylidenepyrazolidin-3-ones as potential cytotoxic agents is described. Target compounds were synthesized from the corresponding 4-diethoxyphosphorylpyrazolidin-3-ones which were used as Horner–Wadsworth–Emmons ­reagents for the olefination of formaldehyde. 4-Phosphorylpyrazolidin-3-ones were, in turn, obtained starting from the sodium salt of ethyl 2-diethoxyphosphoryl-3-hydroxy-2-propenoate, ethyl 2-acyl-2-diethoxyphosphorylacetates, or 3-methoxy-2-diethoxyphosphorylacrylate and monosubstituted or 1,2-disubstituted hydrazines.enalkylationantitumor agentsheterocycleslactamsMichael additionolefinationArtykuł