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Synlett 2010(12): 1793-1796  
DOI: 10.1055/s-0030-1258088
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Preparation of Pyrimidine-N-oxides by Condensation of Functionalized Enamides with Hydroxylamine Hydrochloride

Reinhold Zimmer, Tilman Lechel, Giaime Rancan, Mrinal K. Bera, Hans-Ulrich Reissig*
Freie Universität Berlin, Institut für Chemie und Biochemie, Takustr. 3, 14195 Berlin, Germany
Fax: +49(30)83855367; e-Mail: hans.reissig@chemie.fu-berlin.de;
Further Information

Publication History

Received 8 April 2010
Publication Date:
11 June 2010 (online)

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Abstract

β-Alkoxy-β-ketoenamides and hydroxylamine hydrochloride smoothly provide pyrimidine-N-oxides under very mild conditions. Alkyl, aryl, and heteroaryl substituents are compatible with this new method. By treatment with acetic acid anhydride these pyrimidine-N-oxides undergo a rearrangement furnishing highly functionalized 6-acetoxymethyl-substituted pyrimidine derivatives in good yields. Our method, which is based on a three-component reaction of alkoxyallenes, nitriles, and carboxylic acids, therefore constitutes a highly flexible route to densely substituted pyrimidine derivatives.

Key words

pyrimidines - N-oxides - enamides - hydroxylamine - condensation - 3,3-sigmatropic rearrangement

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