Phosphate salts of AB-polybenzoxazole monomer
    36.
    发明授权
    Phosphate salts of AB-polybenzoxazole monomer 失效
    AB-聚苯并恶唑单体的磷酸盐

    公开(公告)号:US5068384A

    公开(公告)日:1991-11-26

    申请号:US546596

    申请日:1990-06-29

    IPC分类号: C07C227/06 C08G73/22

    CPC分类号: C07C227/06 C08G73/22

    摘要: AB-polybenzoxazole monomer, such as 3-amino-4-hydroxybenzoic acid, can be synthesized in high yields from a hydroxy-benzoic acid or related compound in a three-step process of (1) nitration, (2) hydrolysis of the ester, and (3) reduction of the nitro moiety. The monomer is conveniently recovered as a phosphate salt in high purity by precipitating and recrystallizing from a phosphoric acid solution.

    摘要翻译: 可以在(1)硝化的三步法中,从羟基 - 苯甲酸或相关化合物以高产率合成AB-聚苯并恶唑单体,例如3-氨基-4-羟基苯甲酸,(2)酯的水解 ,和(3)还原硝基部分。 通过从磷酸溶液中沉淀和重结晶,可以方便地将单体作为高纯度的磷酸盐回收。