Preparation of 3-chlorophthalic anhydride
    3.
    发明授权
    Preparation of 3-chlorophthalic anhydride 失效
    3-氯邻苯二甲酸酐的制备

    公开(公告)号:US5683553A

    公开(公告)日:1997-11-04

    申请号:US580252

    申请日:1995-12-28

    CPC分类号: C07C51/573

    摘要: A process for preparing essentially pure 3-chlorophthalic anhydride from a mixture in which 3-chlorophthalic anhydride is present in addition to 4,5-dichlorophthalic anhydride, which involves first distilling off a mixture of 3-chlorophthalic anhydride and 4,5-dichlorophthalic anhydride, so that the obtained bottoms is essentially free of 4,5-dichlorophthalic anhydride, and then by distillation of the obtained bottoms, recovering 3-chlorophthalic anhydride in a second distillation step. The starting mixture is preferably prepared without solvent in a melt by incomplete chlorination of phthalic anhydride using FeCl.sub.3 as a catalyst.

    摘要翻译: 除了4,5-二氯邻苯二甲酸酐之外,还存在其中存在3-氯邻苯二甲酸酐的混合物中制备基本上纯的3-氯邻苯二甲酸酐的方法,其涉及首先蒸馏出3-氯邻苯二甲酸酐和4,5-二氯邻苯二甲酸酐的混合物 得到的底物基本上不含4,5-二氯邻苯二甲酸酐,然后蒸馏得到的底物,在第二蒸馏步骤中回收3-氯邻苯二甲酸酐。 起始混合物优选通过使用FeCl 3作为催化剂不完全氯化邻苯二甲酸酐而在熔体中无溶剂制备。