Method for producing 2,6-dihydroxybenzoic acid
    6.
    发明授权
    Method for producing 2,6-dihydroxybenzoic acid 失效
    2,6-二羟基苯甲酸的制备方法

    公开(公告)号:US5304677A

    公开(公告)日:1994-04-19

    申请号:US7782

    申请日:1993-01-22

    CPC分类号: C07C51/487

    摘要: A method for producing 2,6-dihydroxybenzoic acid, which comprises heating an aqueous solution which contains a mixture of 2,6-dihydroxybenzoic acid and 2,4-dihydroxybenzoic acid and has a pH value of 4 or more, to selectively decompose 2,4-dihydroxybenzoic acid, and separating 2,6-dihydroxybenzoic acid from the decomposition reaction mixture.

    摘要翻译: 制备2,6-二羟基苯甲酸的方法,其包括加热含有2,6-二羟基苯甲酸和2,4-二羟基苯甲酸的混合物并且pH值为4以上的水溶液以选择性分解2, 并从分解反应混合物中分离出2,6-二羟基苯甲酸。

    Method for preparing solid p-disodium hydroxybenzoate
    7.
    发明授权
    Method for preparing solid p-disodium hydroxybenzoate 失效
    固体对羟基苯甲酸二钠制备方法

    公开(公告)号:US4731475A

    公开(公告)日:1988-03-15

    申请号:US43323

    申请日:1987-04-28

    CPC分类号: C07C51/00 C07C51/093

    摘要: The present invention provides a method for preparing solid p-disodium hydroxybenzoate which is characterized by comprising the steps of reacting phenol, carbon tetrachloride in an amount of 0.9 to 1.2 moles per mole of phenol and sodium hydroxide in an amount of 7 to 20 moles per mole of phenol prior to the reaction in an aqueous liquid containing 10 to 40% by weight of p-disodium hydroxybenzoate and/or sodium chloride in the presence of a transition metal powder in an amount of 0.01 to 1.00% by weight based on the weight of a reaction system at a reaction temperature of 50.degree. to 150.degree. C.; cooling the resulting reaction mixture to a level of -20.degree. to +20.degree. C.; and separating said p-disodium hydroxybenzoate therefrom.