| 摘要 |
A process for continuous production of piperidine carboxylic acid esters is provided to improve the yield, economic efficiency and selectivity of production by inhibiting lowering of the catalyst activity and continuously maintaining life of the catalyst. The piperidine carboxylic acid esters are continuously produced by continuously hydrogenating pyridine carboxylic acid esters in solvent in the presence of 1-30 wt.% ruthenium-carrying catalyst having CO adsorption amount of at least 0.6 cc/g cat. under the conditions including temperature of 5-500 deg. C, hydrogen pressure of 5-500 atmospheric pressure, and weight hour space velocity(WHSV) of 0.1-30 h^-1 in a fixed bed continuous reactor, wherein the solvent is ether such as tetrahydrofuran, diglyme and dioxan; alcohol such as methanol, ethanol and isopropanol; or saturated hydrocarbon such as hexane, heptanes and cyclohexane. The support of the ruthenium-carrying catalyst is an inorganic oxide such as silica, alumina, zirconia, titania, zinc oxide, chromium oxide, alkali metal oxide or alkali earth metal oxide, or a carbon, and the ruthenium-carrying catalyst has a circular, cylindrical or granular shape. |
