Process for the manufacture of substituted maleimides
    5.
    发明授权
    Process for the manufacture of substituted maleimides 失效
    制备取代的马来酰亚胺的方法

    公开(公告)号:US5306828A

    公开(公告)日:1994-04-26

    申请号:US835198

    申请日:1992-02-13

    CPC分类号: C07D207/448 Y02P20/582

    摘要: In a process for the preparation of substituted maleimides the corresponding amines are reacted with maleic anhydride and the thermal imidization of the resulting substituted amic-acids is effected in a mixed apolar/polar aprotic solvent medium in the presence of an acid catalyst, a substantial portion of the apolar solvent is subsequently selectively removed from the reaction mixture and most of the final product is precipitated.

    摘要翻译: 在制备取代的马来酰亚胺的方法中,相应的胺与马来酸酐反应,所得到的取代的酰胺酸的酰亚胺化在混合的非极性/非极性非质子溶剂介质中在酸催化剂的存在下进行, 的非极性溶剂随后从反应混合物中选择性地除去,并且大部分最终产物沉淀。

    Intermediates to tetrabromophthalic anhydride and process therefor
    6.
    发明授权
    Intermediates to tetrabromophthalic anhydride and process therefor 失效
    中间体至四溴邻苯二甲酸酐及其工艺

    公开(公告)号:US5225573A

    公开(公告)日:1993-07-06

    申请号:US808073

    申请日:1991-12-10

    摘要: Tetrabromophthalic anhydride and the corresponding free acid are propared by oxidizing in the liquid phase a compound of the formula ##STR1## each of A and A' is independently selected from oxygen, OH or acetoxy; each of R and R' is independently selected from H, OH, alkyl, alkylidene or oxygen;x is 0 or 1; y is 3-x; and R.sub.y and R'.sub.y may together form a closed alicyclic or heterocyclic ring structure.Mixtures of two or more compounds of formula (I), optionally in the presence of an oxidation catalyst, can also be employed as the starting material.

    摘要翻译: 四溴邻苯二甲酸酐和相应的游离酸通过在液相中氧化得到式(I)的化合物,其中:A和A'各自独立地选自氧,OH或乙酰氧基; R和R'各自独立地选自H,OH,烷基,亚烷基或氧; x为0或1; y是3-x; 而Ry和R'y可以一起形成封闭的脂环族或杂环结构。 两种或更多种式(I)化合物(任选在氧化催化剂存在下)的混合物也可用作起始原料。