Studies on Insecticides. V. Synthesis of 2-Piperidone Derivatives.

Abstract

Hydrogenation of 2 (1H)-pyridones was carried out in methanol over Raney nickel at 120 atm. and 200∼240°and gave 2-piperidone derivatives. When the reduction temperature was raised to 280°, hydrogenation of carbonyl group took place, followed by N-methylation of the resulting piperidine derivative was observed. On the other hand, when the reaction temperature was kept below 180°, the starting material was recovered unchanged. By the action of acetic anhydride on 4-ethylpyridine 1-oxide, 4-(1-hydroxyethyl) pyridine and 4-ethyl-3-hydroxypyridine were obtained, while 4-methoxycarbonylpyridine 1-oxide gave 4-methoxycarbonyl-2 (1H)-pyridone.