Reactions of 1.3-Dicarbonyl Compounds with Hexamethylenetetramine
--Facile Synthetic Method for 1,4-Dihydropyridine Derivatives and Their Air Oxidation--
Masayuki NOMURA*, Shinichi NAKATA and Fumio HAMADA
Faculty of Engineering and Resource Science, Akita University; 1-1 Tegatagakuen-cho, Akita-shi 010-8502 Japan
The reaction of acetoacetates or benzoylacetone with hexamethylenetetramine in aqueous ammonium carbonate solution at room temperature gave 2,6-dimethyl-1,4-dihydropyridines (DHP) directly. These DHPs were oxidized to the corresponding pyridine derivatives quantitatively by air oxidation. Reaction machanism is also discussed.