Mloston G.,University of Leodz |
Jasinski M.,University of Leodz |
Heimgartner H.,University of Zürich
European Journal of Organic Chemistry | Year: 2011
A new method for the preparation of 1,4,5-trisubstituted (imidazol-2-yl)acetates, based on the reaction of the corresponding imidazole 3-oxides with dimethyl acetylenedicarboxylate (DMAD) is described. Formation of the products is rationalized by a formal 1,3-dipolar cycloaddition and subsequent oxaloyl cleavage. 1,4,5-Trisubstituted imidazole 3-oxides bearing an electron-withdrawing substituent at C(4), easily react with dimethyl acetylenedicarboxylate (DMAD), yielding the corresponding oxobutanoates, which subsequently, in a one-pot procedure undergo hydrolysis through an "oxaloyl cleavage" mode. New (imidazol-2-yl)acetates were isolated in high yields. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Lewkowski J.,University of Leodz |
Dzigielewski M.,University of Leodz
Phosphorus, Sulfur and Silicon and the Related Elements | Year: 2010
The preparation of 1,4-phenylene-bis[1-(alkoxycarbonyl)alkylamino- methanephosphonous acids] by the addition of hypophosphorous acid to terephthalylidene-bis[1-(alkoxycar bonyl)alkylamines] is described. Despite expectations, no chiral assistance of the amino acid ester moiety is observed.