Studies on Isocyanides and RelatedCompounds: A Facile Synthesis of 1,6-Dihydro-6-oxopyrazine-2-carboxylicAcid Derivatives via Ugi Four-Component Condensation
作者:Stefano Marcaccini、Cristina Faggi、María García-Valverde、Roberto Pepino、Ma. Cruz Pozo
DOI:10.1055/s-2003-40525
日期:——
The Ugi four-component condensation (U-4CC) between arylglyoxals 7, amines 6, benzoylformic acid (4) and isocyanides 5 afforded the expected products 8 which were cyclized in a 5+1 fashion with ammonium acetate to give I,N-disubstituted 4-aryl-1,6-dihydro-6-oxo-5-phenylpyrazine-2-carboxamides 9 in good yields. Evidence for the assigned structures 9 was provided by 1 3 C NMR spectra and X-ray analysis
芳基乙二醛 7、胺 6、苯甲酰甲酸 (4) 和异氰化物 5 之间的 Ugi 四组分缩合 (U-4CC) 得到预期的产物 8,其以 5+1 方式与乙酸铵环化得到 I,N-二取代4-aryl-1,6-dihydro-6-oxo-5-phenylpyrazine-2-carboxamides 9 收率良好。指定结构 9 的证据由 1 3 C NMR 光谱和 9a 的 X 射线分析提供。