Process for the production of 2,3,5-trimethylhydroquinone diesters
    6.
    发明授权
    Process for the production of 2,3,5-trimethylhydroquinone diesters 失效
    制备2,3,5-三甲基氢醌二酯的方法

    公开(公告)号:US06417409B1

    公开(公告)日:2002-07-09

    申请号:US09502229

    申请日:2000-02-11

    IPC分类号: C07C3700

    摘要: The invention relates to an improved process for the production of 2,3,5-trimethylhydroquinone diesters by rearrangement of 2,6,6-trimethyl-2-cyclohexene-1,4-dione (4-oxoisophorone, ketoisophorone) in the presence of a dissolved, acidic catalyst and an acylating agent, such as for example carboxylic anhydrides or carboxylic acid halides. The 2,3,5-trimethylhydroquinone diester can optionally then be saponified to give free 2,3,5-trimethylhydroquinone (TMHQ), which is a valuable building block in the synthesis of vitamin E.

    摘要翻译: 本发明涉及通过在2,6,6-三甲基-2-环己烯-1,4-二酮(4-氧代异佛尔酮,酮异佛尔酮)的存在下重排来制备2,3,5-三甲基氢醌二酯的改进方法 溶解的酸性催化剂和酰化剂,例如羧酸酐或羧酸卤化物。 可以任选地将2,3,5-三甲基氢醌二酯皂化,得到游离的2,3,5-三甲基氢醌(TMHQ),其是维生素E合成中的有价值的结构单元。

    Process for the production of 2,3,5-trimethylhydroquinone diesters
    8.
    发明授权
    Process for the production of 2,3,5-trimethylhydroquinone diesters 失效
    制备2,3,5-三甲基氢醌二酯的方法

    公开(公告)号:US06316661B1

    公开(公告)日:2001-11-13

    申请号:US09493065

    申请日:2000-01-28

    IPC分类号: C07C6900

    摘要: A process for the production of 2,3,5-trimethylhydroquinone diesters by aromatization of 2,6,6-trimethyl-2-cyclohexene-1,4-dione (4-oxoisophorone, ketoisophorone, KIP) with an acylating agent and an acidic soluble or insoluble catalyst, which process may be operated alternatively continuously or discontinuously. The process includes the following steps: a) a carboxylic anhydride having a C1 to C4 alkyl residue is used as the acylating agent, b) after the reaction, a proportion of the resultant carboxylic acid is optionally removed by distillation, c) the reaction solution is cooled, d) the product which has crystallized out is separated and washed, and e) the filtrate is returned to step a).

    摘要翻译: 通过2,6,6-三甲基-2-环己烯-1,4-二酮(4-氧异佛尔酮,酮异佛尔酮,KIP)与酰化剂和酸性化合物的芳构化生产2,3,5-三甲基氢醌二酯的方法 可溶或不溶的催化剂,该方法可以交替连续或不连续地操作。 该方法包括以下步骤:a)具有C1至C4烷基残基的羧酸酐用作酰化剂,b)反应后,任选地通过蒸馏除去所得羧酸的一部分,c)反应溶液 被冷却,d)结晶出来的产物被分离和洗涤,e)将滤液返回到步骤a)。