An efficient method for the construction of polysubstituted 4-pyridones via self-condensation of β-keto amides mediated by P<sub>2</sub>O<sub>5</sub> and catalyzed by zinc bromide
作者:Liquan Tan、Peng Zhou、Cui Chen、Weibing Liu
DOI:10.3762/bjoc.9.304
日期:——
is presented for the synthesis of polysubstituted 4-pyridones and 2-pyridones from beta-keto amides. A variety of beta-keto amides are used in this approach, and a wide range of functionalized 4-pyridones and 2-pyridones were obtained in good to excellent yields. When employing the N-aryl beta-keto amides as the substrates in this protocol, 4-pyridones are resulted, however, when using N-aliphatic-substituted
Mediated by sodium persulfate (Na(2)S(2)0(8)), a series of polysubstituted 4-pyridones were synthesized via self-condensation of N-aryl acetoacetamides, during which a novel N to C 1,3-acyl migration should be involved. The structure of 4-pyridone was unequivocally confirmed by X-ray diffraction analysis. However, the self-condensation of N-benzyl acetoacetamides under the same condition gave polysubstituted 2-pyridones instead of 4-pyridones.
PIERCE, J. B.;ARIYAN, Z. S.;OVENDEN, G. S., J. MED. CHEM., 1982, 25, N 2, 131-136