Process to make UV radiation absorbing 2-phenyl-1,2,3,-benzotriazoles

摘要

The invention relates to an improved process for the manufacture of novel benzotriazoles as well to novel benzotriazoles obtained by the novel process. This novel economical process provides products in high purity and yields.;

主权项

1. A process for the manufacture of benzotriazole derivatives of formula (Ib): said process comprising the step of reacting a 2-(2H-benzotriazol-2-yl)-6-chloromethyl-phenol derivative of formula (IIb): with an alcohol of the formula R5—OH in the presence of a base which is at least one selected from the group consisting of an alkali metal carbonate, an alkaline earth metal carbonate, an alkali metal bicarbonate and an alkaline earth metal bicarbonate, wherein in the formulas: R2 is hydrogen; C1-30 alkyl; C1-5 alkoxy; C1-5 alkoxycarbonyl; C5-7 cycloalkyl; C6-10 aryl or aralkyl; R3 is hydrogen; C1-5alkyl; C1-5alkoxy or halogen; R4 is hydrogen or C1-5alkyl; and R5 is C1-30alkyl or C5-10cycloalkyl.