| 摘要 |
PURPOSE:To vapor-phase catalytic oxidation of a ketone bearing a methylene group adjacent to the carbonyl with oxygen is conducted in the presence of a catalyst of tricobalt tetroxide to produce an alpha-diketone used as an intermediate of imidazole in high selectivity. CONSTITUTION:The reactor is filled with a catalyst of tricobalt tetroxide and a gas of ketone bearing a methylene group adjacent to the carbonyl and oxygen are introduced into the reactor at a space rate of 300-5,000hr<-1>. The resultant reaction mixture is absorbed in water or organic solvent and they are subjected to distillation in accordance with usual process to give an alpha-diketone such as diacetyl. The tricobalt tetroxide catalyst is prepared by adding aqueous ammonium carbonate to aqueous cobalt nitrate, filtering and washing the resultant cobalt carbonate precipitation, followed by drying and calcination. |
