Processes for the preparation of benzotriazole UV absorbers
    1.
    发明授权
    Processes for the preparation of benzotriazole UV absorbers 失效
    制备苯并三唑紫外线吸收剂的方法

    公开(公告)号:US06815550B2

    公开(公告)日:2004-11-09

    申请号:US10315693

    申请日:2002-12-10

    IPC分类号: C07D24920

    CPC分类号: C07D249/20 C07C245/08

    摘要: Provided is a process for preparing 2H-benzotriazole UV absorbers containing a perfluoroalkyl moiety at the 5-position of the benzoic ring, for example a trifluoromethyl group, which involves digitizing the perfluoroalkyl substituted o-nitroaniline using concentrated sulfuric acid plus sodium nitrite or nitrosylsulfuric acid to form the corresponding monoazobenzene intermediate via the diazonium salt intermediate which is reduced to the corresponding 5-perfluoroalkyl substituted 2H-benzotriazole UV absorber compound by conventional reduction means. Also provided is a novel one-pot, multiphase reaction for the preparation of 2(2-nitrophenylazo) substituted phenols, which are precursors for 2H-benzotriazole UV absorbers.

    摘要翻译: 提供了制备在苯甲酸环的5位上含有全氟烷基部分的2H-苯并三唑UV吸收剂的方法,例如三氟甲基,其涉及使用浓硫酸加亚硝酸钠或亚硝酰基硫酸将全氟烷基取代的邻硝基苯胺数字化 通过重氮盐中间体形成相应的单偶氮苯中间体,其通过常规还原方法还原成相应的5-全氟烷基取代的2H-苯并三唑UV吸收剂化合物。 还提供了用于制备2(2-硝基苯基偶氮)取代的酚的新颖的一锅多相反应,其是2H-苯并三唑UV吸收剂的前体。