申请人:Chemipro Kasei Kaisha, Ltd.
公开号:US04943637A1
公开(公告)日:1990-07-24
This invention relates to a method for preparing a 2-phenylbenzotriazole of formula I, ##STR1## (wherein R.sub.1 represents hydrogen or chlorine atom, a lower alkyl group having a carbon number of 1 to 4, a lower alkoxy group having a carbon number of 1 to 4, carboxyl group, or sulfonic acid group; R.sub.2 represents hydrogen or chlorine atom, a lower alkyl group having a carbon number of 1 to 4, or a lower alkoxy group having a carbon number of 1 to 4; R.sub.3 represents hydrogen or chlorine atom, an alkyl group having a carbon number of 1 to 12, a lower alkoxyl group having a carbon number of 1 to 4, phenyl group, a phenyl group substituted with an alkyl group having a carbon number of 1 to 8, phenoxy group, or a phenylalkyl group, the alkyl part of which has a carbon number of 1 to 4; R.sub.4 represents hydrogen or chlorine atom, hydroxyl group, or a lower alkoxy group having a carbon number of 1 to 4; and R.sub.5 represents hydrogen atom, an alkyl group having a carbon number of 1 to 12, or a phenylalkyl group, the alkyl part of which has a carbon number of 1 to 4), which comprises reducing an o-nitroazobenzene of formula III, ##STR2## (wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are as defined above) with at least one selected from the group consisting of primary and secondary alcohol reducing agents in the presence of an aromatic ketone catalyst and base. This invention further relates to a method for preparing a 2-phenylbenzotriazole of formula I as defined above, which comprises reducing 1 mole 2-phenylbenzotriazole-N-oxide of formula II, ##STR3## (wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are as defined above) with 0.4 to 0.7 mole primary alcohol and/or 0.8 to 1.4 mole secondary alcohol in the presence of an aromatic ketone catalyst and base. This invention still further relates to a method for preparing a 2-phenylbenzotriazole-N-oxide of formula II as defined above, which comprises reducing 1 mole o-nitroazobenzene of formula III as defined above with 0.4 to 0.7 mole primary alcohol and/or 0.8 to 1.4 mole secondary alcohol in the presence of an aromatic ketone catalyst and base.
这项发明涉及一种制备式I的2-苯基苯并三唑的方法,其中R₁代表氢原子或氯原子,具有1到4个碳原子的低烷基基团,具有1到4个碳原子的低烷氧基团,羧基或磺酸基;R₂代表氢原子或氯原子,具有1到4个碳原子的低烷基基团,或具有1到4个碳原子的低烷氧基团;R₃代表氢原子或氯原子,具有1到12个碳原子的烷基基团,具有1到4个碳原子的低烷氧基团,苯基,带有1到8个碳原子的烷基基团取代的苯基,苯氧基,或苯基烷基基团,其烷基部分具有1到4个碳原子;R₄代表氢原子或氯原子,羟基,或具有1到4个碳原子的低烷氧基团;R₅代表氢原子,具有1到12个碳原子的烷基基团,或苯基烷基基团,其烷基部分具有1到4个碳原子的烷基基团。该方法包括在芳香酮催化剂和碱存在下,用来自主要和次要醇还原剂组成的群体中至少一种,还原式III的o-硝基偶氮苯,其中R₁、R₂、R₃、R₄和R₅如上所定义。这项发明还涉及一种制备上述定义的式I的2-苯基苯并三唑的方法,其中包括在芳香酮催化剂和碱存在下,用0.4到0.7摩尔主要醇和/或0.8到1.4摩尔次要醇还原1摩尔的式II的2-苯基苯并三唑-N-氧化物,其中R₁、R₂、R₃、R₄和R₅如上所定义。这项发明还涉及一种制备上述定义的式II的2-苯基苯并三唑-N-氧化物的方法,其中包括在芳香酮催化剂和碱存在下,用0.4到0.7摩尔主要醇和/或0.8到1.4摩尔次要醇还原1摩尔的式III的o-硝基偶氮苯,如上所定义。