Oxidation of 4-(1, 1-Ethylenedioxyethyl)-and 4-(Ethylenedioxymethyl)-1-methylpyridinium Salts.

抄録

The preparation of 4-ethyl-and 4-methyl-2 (1H)-pyridones from 4-acetyl-and 4-formyl-pyridine, respectively, was described. Thus the 4-acylpyridines were converted to their etheylene ketal derivatives by the standard method, which were then treated with dimethyl sulfate to give the corresponding 1-methylpyridinium salts. The quaternary salts thus obtained underwent smooth oxidation by alkaline potassium ferricyanide to furnish the 2 (1H)-pyridones, from which 4-acetyl and 4-formyl compounds were recovered through mild acid hydrolysis, and were then reduced according to Huang-Minlon, thus yielding 4-ethyl-and 4-methyl-2 (1H)-pyridones in good yields. Yields were good throughout the entire series of reactions.