Preparation of Pyrimidine-N-oxides by Condensation of Functionalized Enamides with Hydroxylamine Hydrochloride
作者:Hans-Ulrich Reissig、Reinhold Zimmer、Tilman Lechel、Giaime Rancan、Mrinal Bera
DOI:10.1055/s-0030-1258088
日期:2010.7
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,
A Route to Alkenyl-Substituted 4-Hydroxypyridine and Pyrimidine Derivatives via Three-Component Access to β-Alkoxy-β-ketoenamides
作者:Hans-Ulrich Reissig、Mrinal Bera
DOI:10.1055/s-0029-1218787
日期:2010.7
β-unsaturated carboxylic acids. Their subsequent treatment with trimethylsilyl triflate and base provided 6-alkenyl-4-hydroxypyridine derivatives that were converted into the corresponding nonaflates. Alternatively, condensation of β-alkoxy-β-ketoenamides with an ammonium salt led to the smooth formation of alkenyl-substituted pyrimidine derivatives. The alkenyl group in pyridine or pyrimidine derivatives allows