申请人:——
公开号:US20030120083A1
公开(公告)日:2003-06-26
Provided is a process for preparing 2H-benzotriazole UV absorbers containing a perfluoroalkyl moiety at the 5-position of the benzo ring, for example a trifluoromethyl group, which involves diazotizing 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.
提供了一种制备含有苯环5位的全氟烷基(例如三氟甲基)的2H-苯并三唑紫外线吸收剂的方法,其中使用浓硫酸加亚硝酸钠或亚硝基硫酸制取全氟烷基取代的邻硝基苯胺的重氮化物中间体,通过还原手段将中间体还原为相应的5-全氟烷基取代的2H-苯并三唑紫外线吸收剂化合物。还提供了一种新型的一锅法多相反应,用于制备2(2-硝基苯偶氮)取代酚,其是2H-苯并三唑紫外线吸收剂的前体。