[EN] METHOD FOR PREPARING 2-(2-HYDROXYPHENYL)-2H-BENZOTRIAZOLE<br/>[FR] PROCEDE POUR PREPARER DU 2-(2-HYDROXYPHENYL)-2H-BENZOTRIAZOLE
申请人:LG CHEMICAL LTD
公开号:WO2002055508A1
公开(公告)日:2002-07-18
This invention provides a method for preparing 2-(2-hydroxyphenyl)-2H-benzotriazole of formula (I) below, consisting of steps of: a) performing a first reduction in which hydrazine hydrate is added to a compound of formula (II) below with or without a phase transition catalyst in the presence of solvents which include a nonpolar solvent, water, and an alkaline compound, thereby preparing a compound of formula (III) below; and b) performing a second reduction in which water is added to the compound of formula (III) prepared in step a), and then zinc powder and sulfuric acid are added thereto with or without the phase transition catalyst, wherein, X is halogen or hydrogen; R is hydrogen, C1-C12 alkyl, C5-C8 cycloalkyl, phenyl, or phenyl-C1-C4 alkyl; and R' is C1-C12 alkyl, C5-C8 cycloalkyl, phenyl, or phenyl-C1-C4 alkyl.