Process for the synthesis of 2,6-dichloro-5-fluoronicotinic acid and
2,6-dichloro-5-fluoronicotinoyl chloride
    4.
    发明授权
    Process for the synthesis of 2,6-dichloro-5-fluoronicotinic acid and 2,6-dichloro-5-fluoronicotinoyl chloride 失效
    合成2,6-二氯-5-氟烟酸和2,6-二氯-5-氟烟酰氯的方法

    公开(公告)号:US5204478A

    公开(公告)日:1993-04-20

    申请号:US932452

    申请日:1992-08-20

    申请人: Rex A. Jennings

    发明人: Rex A. Jennings

    CPC分类号: C07D213/78 C07D213/80

    摘要: An improved process for the preparation of 2,6-dichloro-5-fluoronicotinoyl chloride is described where a 2,6-dihydroxy-5-fluoronicotinic acid ester is converted in one step using phosphorus oxychloride and a lithium reagent to 2,6-dichloro-5-fluoronicotinoyl chloride and subsequent basic hydrolysis affords 2,6-dichloro-5-fluoronicotinic acid.

    摘要翻译: 描述了一种制备2,6-二氯-5-氟烟酰氯的改进方法,其中2,6-二羟基-5-氟烟酸酯在一步中使用磷酰氯和锂试剂转化成2,6-二氯 -5-氟烟酰氯和随后的碱性水解得到2,6-二氯-5-氟烟酸。

    Podophyllotoxin purification process
    7.
    发明授权
    Podophyllotoxin purification process 失效
    鬼臼毒素净化过程

    公开(公告)号:US5057616A

    公开(公告)日:1991-10-15

    申请号:US415170

    申请日:1989-09-29

    IPC分类号: C07D493/04

    CPC分类号: C07D493/04

    摘要: Podophyllotoxin is recovered from podophyllum resin with improved efficiency by adsorbing impurities out of a solution using a solid adsorbent, preferably alumina. This improvement finds application in an overall process for purifying podophyllotoxin from podophyllum resin in which the podophyllotoxin is first crystallized from the podophyllum resin, the crystals so formed are dissolved and subjected to the solid adsorbent treatment, crystals are then recovered and optionally recrystallized and dried to give the desired product.

    摘要翻译: 通过使用固体吸附剂,优选氧化铝从溶液中吸附杂质,从鬼臼树脂中回收鬼臼毒素,效率提高。 这种改进可以应用于从鬼臼树脂中首先从鬼臼树脂中提取鬼臼毒素的鬼臼树脂净化鬼臼毒素的整体过程中,将形成的晶体溶解并进行固体吸附处理,然后回收晶体并任选重结晶并干燥至 给出所需的产品。