| 摘要 |
1,125,735. Pyridines. IMPERIAL CHEMICAL INDUSTRIES Ltd. 21 Aug., 1967 [5 Sept., 1966], No. 39582/66. Heading C2C. Pyridine or substituted pyridines are prepared by reacting piparidine, a tetrahydropyridine or a substituted derivative thereof with molecular oxygen in the vapour phase at elevated temperature. Preferably, at least 0.5 mol. of oxygen is used for each mol. of hydrogen to be removed from the starting material. It is preferred to carry out the process in the presence of a catalyst, e.g. silica, alumina or silica-alumina, with or without metals, oxides or salts as impregnants. |
