Compounds of formula I or II where R is an aryl moiety, such as phenyl, naphthyl or biphenylyl, or is phenyl substituted by one or more trifluoromethyl, bromo or cyano, and E1 and E2 are independently hydrogen, alkyl, aralkyl and the like are prepared by reaction of a benzotriazole substituted on the 5-position of the benzo ring by a halogen atom with a arylboronic acid or ester in the presence of a transition-metal catalyst, such as palladium (II) diacetate. The benzotriazole compounds of formula I are particularly efficacious as stabilizers for automotive coatings and candle wax.