Reaction of 4-methylamino-5,6-dihydropyridinone with acetyl chloride yielded exclusively the 3-acetyl derivative. When the methylamino group of the latter was removed by alkaline hydrolysis, a mixture of two hydroxy derivatives was formed. Those cyclized upon treatment with hydroxylamine exclusively to the isoxazolo[4,5-c]pyridinone, whereas the 4-methylamino analogue yielded, depending on pH, mainly the isoxazolo[4,3-c]pyridinone or the isoxazolo[4,5-c]pyridinone. The configurations of the latter compounds were established by NMR experiments.
Reaction of 4-methylamino-5,6-dihydropyridinone with acetyl chloride yielded exclusively the 3-acetyl derivative. When the methylamino group of the latter was removed by alkaline hydrolysis, a mixture of two hydroxy derivatives was formed. Those cyclized upon treatment with hydroxylamine exclusively to the isoxazolo[4,5-c]pyridinone, whereas the 4-methylamino analogue yielded, depending on pH, mainly the isoxazolo[4,3-c]pyridinone or the isoxazolo[4,5-c]pyridinone. The configurations of the latter compounds were established by NMR experiments.
作者:Robert Weis、Klaus Schweiger、Walter M. F. Fabian
DOI:10.1007/pl00010140
日期:1998.12
Reaction of 4-methylamino-5,6-dihydropyridinone with acetyl chloride yielded exclusively the 3-acetyl derivative. When the methylamino group of the latter was removed by alkaline hydrolysis, a mixture of two hydroxy derivatives was formed. Those cyclized upon treatment with hydroxylamine exclusively to the isoxazolo[4,5-c]pyridinone, whereas the 4-methylamino analogue yielded, depending on pH, mainly the isoxazolo[4,3-c]pyridinone or the isoxazolo[4,5-c]pyridinone. The configurations of the latter compounds were established by NMR experiments.