A simple, two-step synthesis of 4,6-disubstituted pyridazin-3(2H)-ones starting from 2-diethoxyphosphoryl-4-oxoalkanoates and hydrazines is described. The intermediate 4-diethoxyphosphoryl-4,5-dihydropyridazin-3(2H)-ones obtained in this way are used in a Horner-Wadsworth-Emmons olefination of aldehydes to give a variety of disubstituted pyridazin-3(2H)-ones.
5-Alkyl- and 5-arylalkyl-3-methylenedihydrofuran-2-ones 13a-e, 3-alkylidenedihydrofuran-2-ones 18a-c, and 3-methylenepyrrolidin-2-ones 16a-e were synthesized utilizing ethyl 2-diethoxyphosphoryl-4-nitroalkanoates 9a-e as common intermediates. All obtained compounds were tested against L-1210, HL-60, and NALM-6 leukemia cells. The highest cytotoxic activity was observed for 3-methylenefuranones 13d,e bearing benzyl or 3,4-dimethoxyphenylmethyl substituents at position 5, with IC50 values of 5.4 and 6.0 mu M, respectively. Contrary to the literature reports, no enhancement in activity due to the presence of a hydroxy group was found when the cytotoxicity of furanones 13a,b,d and 5-(1'-hydroxyalkyl)-3-methylenedihydrofuran-2-ones 6a,b,d was compared. The anticancer activity of pyrrolidinones 16a-e and 3-alkylidenefuranones 18a-c was much weaker than that of furanones 13a-e.
New, diastereoselective synthesis of 1-alkyl-5-alkylidene-3-methylidenepyrrolidin-2-ones
作者:Anna Albrecht、Jacek Kędzia、Jacek F. Koszuk、Edyta Warzycha、Tomasz Janecki
DOI:10.1016/j.tetlet.2006.02.006
日期:2006.4
The diastereoselective synthesis of 1-alkyl-5-alkylidene-3-methylidenepyrrolidin-2-ones was readily accomplished in a two-step reaction sequence consisting of the reaction of 2-diethoxyphosphoryl-4-oxoalkanoates with amines followed by Horner-Wadsworth-Emmons olefination of formaldehyde using the intermediate 1-alkyl-5-alkylidene-3-diethoxyphosphorylpyrrolidin-2-ones. (c) 2006 Elsevier Ltd. All rights reserved.