| 摘要 |
PURPOSE:To obtain the subject compounds which are an intermediate for producing medicines, agricultural chemicals, in high purity and good yield by one-stage reaction, by directly dehydrogenating a substituted 2-acyl-1,3-cyclohexanedione as a raw material. CONSTITUTION:A substituted 2-acyl-1,3-cyclohexanedione expressed by formula I (R<1> is alkyl, aralkyl or aryl; R<2> is H, alkyl, alkoxy or acylamino) (e.g., 2- acetyl-1,3-cyclohexanedione) is directly dehydrogenated in the presence of a catalyst or dehydrogenating agent to afford the aimed compounds expressed by formula II. In the dehydrogenating reaction, the formed hydrogen is removed by using, e.g., a method for removing the hydrogen together with 2-propanol vapor and/or N. The temperature for the dehydrogenating reaction is normally 100-250 deg.C. Furthermore, a group VIII metal-containing catalyst, such as nickel, is preferably used as the catalyst in an amount of 0.05-0.5pt.wt. based on the compound expressed by formula I. |
