| 摘要 |
PURPOSE:To obtain the subject compounds useful as an ultraviolet light absorber in high yield under mild conditions without any side reaction by reducing an o-nitroazobenzene derivative in the presence of a specific catalyst and a specified cocatalyst using specific alcohols. CONSTITUTION:A compound expressed by formula I (R1 is H, Cl, 1-4C lower alkyl, etc.; R2 is H, Cl, etc.; R3 is H, Cl, 1-12C alkyl, etc.; R4 is H, Cl, etc.; R5 is H, 1-12C alkyl, etc.) is reduced with a compound selected from >=3C primary and secondary alcohols, in the presence of a catalyst composed of a compound selected from naphthalenes having total >=2 hydroxyl and amino groups or oxides thereof and cyclic ketones adjacent to an aromatic ring, and a cocatalyst selected from benzenes having total >=2 hydroxyl and amino groups and oxides thereof to afford the objective 2-phenylbenzotrizoles expressed by Formula II. |
