Tetrahedron 2009, 65, 2660-2668
Our current interest in the design of original chemical libraries featuring a pyrazole nucleus led us to focus on the chemistry of the 3-alkoxy-5-methylpyrazoles we have recently made readily available. With in mind the preparation of an array of the less accessible 1-arylpyrazol-3-ones, the present report de- scribes the respective nitrogen’s reactivity of various 3-alkoxypyrazoles toward arylation reaction, using arylboronic acids, as well as alkylation reactions using methyl iodide or benzylbromide. The structure assignments of the isomers obtained were achieved using long distance 15N–1H NMR correlation measurements or by the recourse to unambiguous synthetic pathway
