| 摘要 |
<p>1,129,622. #-Pinene. FARBWERKE HOECHST A.G. 20 Jan., 1966 [10 Sept., 1965], No. 2668/66. Heading C5E. #-Pinene is prepared by isomerizingα- pinene in the vapour phase at 140-200‹ C. in the absence of oxygen, in the presence as 1-5 vol. per cent (based on the pinene volume) of hydrogen, and over a palladium/carbon catalyst. The hydrogen serves to regenerate the catalyst and act as a carrier gas. The residence time is suitably 0À1-20 seconds. The feed is suitably a pinene-containing turpentine oil or terpene mixture, or a technical gradeα-pinene. The product, after separation from the catalyst, is passed continuously to a distillation column where #-pinene concentrates andα-pinene is taken off overhead and recycled. The distillation is continued until the #-pinene content has reached the desired level, at which point further distillation will yield pure #-pinene and unconvertedα-pinene which can be rearranged to camphene with titanic acid.</p> |
