PROCESS FOR PREPARING 2-(2'-HYDROXYPHENYL)- BENZOTRIAZOLES FROM 2-NITRO-2'-HYDROXYAZOBENZENES

摘要

AbstractProcess for preparing 2-(2'-hydroxyphenyl)-benzo-triazoles of the formulafrom 2-nitro-2'-hydroxyazobenzenes of the formulawhich comprises reducing a 2-nitro-2'-hydroxyazobenzene com-pound in a strongly basic medium in the presence of an aro-matic dihydroxy or dioxo compound as catalyst and of analcohol having more than one carbon atom. The 2-(2'-hydroxy-phenyl)-benzotriazole compounds are known stabilisers fororganic materials.