PRODUCTION OF 2,2,6,6-TETRAMETHYL-4-OXOPIPERIDINE

PURPOSE:To readily obtain the aimed compound, by reacting acetone or an acidic condensate with ammonia or acetonin in the presence of sulfurous acid, sulfite, hydrogensulfite or pyrosulfite as a catalyst to prodice the titled com pound. CONSTITUTION:Acetone or an acidic condensate thereof is reacted with ammonia or 2,2,4,4,6-pentamethyl-2,3,4,5-tetrahydropyrimidine is used to produce the titled compound useful as an intermediate for light stabilizers of high polymer materials, etc. In the process, >=0.001mol, preferably 0.001-1mol based on 1mol acetone or acetonin, sulfurous acid, sulfite, hydrogensulfite or pyrosulfite is used as a catalyst to advantageously obtain the aimed compound. This method has the following advantages: The reaction proceeds even at a lower temperature than the conventional method and the reaction time is short. The yield of the aimed compound is high without observed coloring. By-products are scarcely formed, etc.