Abstract
Reaction of 6-methyl-2-phenyl-4H-1, 3-oxazin-4-one (I) with active methylene compounds, such as diethyl malonate (IIIa), acetylacetone (IIIb), cyclohexane-1, 3-dione (IIIc), malononitrile (IIId), ethyl acetoacetate (IIIe), ethyl cyanoacetoacetate (IIIf), and cyanoacetophenone (IIIg) afforded pyridone derivatives, such as 3-acetyl-5-ethoxy-carbonyl-4-hydroxy-6-phenyl-2 (1H)-pyridone (IVa), 3, 5-diacetyl-4-methyl-6-phenyl-2 (1H)-pyridone (IVb), 4-acetyl-1-phenyl-6, 7-dihydro-3, 8-(2H, 5H)-isoquinolinedione (IVc), 3-acetyl-4-amino-5-cyano-6-phenyl-2 (1H)-pyridone (IVd), 3-acetyl-5-ethoxycarbonyl-4-methyl 6-phenyl-2 (1H)-pyridone (IVe), 3-acetyl-5-cyano-4-hydroxy-6-phenyl-2 (1H)-pyridone (IVf), and 3-acetyl-5-cyano-4, 6-diphenyl-2 (1H)-pyridone (IVg), respectively. Similarly, 2-ethoxy-2, 6-dimethyl-2H-1, 3-oxazin-4 (3H)-one (II) reacted with IIIa-t under the same conditions to give the corresponding pyridone derivatives (Va-f).
