Synthesis of 2-Substituted Pyridines via a Regiospecific Alkylation, Alkynylation, and Arylation of Pyridine <i>N</i>-Oxides
作者:Hans Andersson、Fredrik Almqvist、Roger Olsson
DOI:10.1021/ol070184n
日期:2007.3.1
Grignard reagents to pyridine N-oxides in THF at room temperature followed by treatment with acetic anhydride at 120 degrees C afforded 2-substituted pyridines in good to high yields. Furthermore, by exchanging acetic anhydride for DMF in the second step, 2-substituted pyridine N-oxides were obtained, as intermediates suitable for addition of a second Grignard reagent for the synthesis of 2,6-disubstituted
[结构:见文字]。在室温下,将格氏试剂依次加入到THF中的吡啶N-氧化物中,然后在120℃下用乙酸酐处理,从而以高至高收率得到2-取代的吡啶。此外,通过在第二步骤中将乙酸酐交换为DMF,获得了2-取代的吡啶N-氧化物,作为适合于添加第二格氏试剂以合成2,6-二取代的吡啶的中间体。