| 摘要 |
PURPOSE:To obtain a 2-phenylbenzotriazole-N-oxide compound useful as a synthetic intermediate for ultraviolet absorber in high purity and yield by reducing an o-nitroazobenzene compound with an alcohol in the presence of a base and a catalyst such as p-aminophenol. CONSTITUTION:A 2-phenylbenzotriazole-N-oxide compound of the formula II can be produced by reducing an o-nitroazobenzene compound of the formula I (R<1> is H, Cl, 1-4C alkyl, etc.; R<2> is H or Cl; R<3> is H, Cl, 1-12C alkyl, phenyl, etc.; R<4> is H, 1-12C alkyl, etc.) with a l-5C alcohol (e.g. isopropyl alcohol) in the presence of a base (e.g. NaOH) and at least one kind of catalyst selected from aminophenols, diaminophenols and their inorganic acid salts. A 2- phenylbenzotriazole compound of the formula III is obtained by further reducing the compound of the formula I or the compound of the formula II with a cocatalyst (e.g. sodium metaborate). |
