Abstract
Thermal-induced dimerization cyclization of ethyl N-(styrylcarbamoyl)acetate derivatives has been investigated, leading to 4-hydroxy-2(1H)-pyridone-3-carboxamide derivatives with good yields in diphenyl ether on 200–210 °C. Ethyl N-(styrylcarbamoyl)acetate derivatives readily provided the intermolecular cyclization products 4-hydroxy-2(1H)-pyridone-3-carboxylates on reflux in xylene. In addition, several related 3-acetyl-4-hydroxy-5-phenylpyridin-2(1H)-ones have been prepared. It provided an efficient preparation of 4-hydroxy-2(1H)-pyridone-3-carboxamide derivatives.
GRAPHICAL ABSTRACT
Notes
a Reaction conditions: compounds 5a (2.0 mmol) was stirred in solvent for the time indicated in Table 1.
b Isolated yield with column chromatography.
a Reaction conditions: compounds 5 (2.0 mmol) was stirred in diphenyl ether at 200–210 °C for the time indicated in Table 2.
b Isolated yield with column chromatography.
Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/lsyc.