Functional polymers, 11. Synthesis and polymerization of 2‐(2‐hydroxy‐5‐vinylphenyl)‐2H‐benzotriazole

Abstract 2‐(2‐Hydroxy‐5‐vinylphenyl)‐2H‐benzotriazole (9) was prepared by a seven step synthesis in about a 25% overall yield starting fromo‐nitroaniline. Diazotization in aqueous HCl gave a diazonium salt which was coupled withp‐ethylphenol to an azo‐dye which was reduced with zinc powder in sodium hydroxide solution to 2‐(2‐hydroxy‐5‐ethylphenyl)‐2H‐benzotriazole (4). This compound was acetylated and then brominated withN‐bromosuccinimide to 2‐[2‐acetoxy‐5‐(1‐bromoethyl)phenyl]‐2H‐benzotriazole (6) which was dehydrobrominated with triethylamine in acetonitrile or tributylamine in dimethylacetamide to the vinyl compound which was hydrolyzed to9. This monomer was readily homopolymerized and copolymerized with styrene and methyl methacrylate using 2,2′‐azobis(2‐methylpropionitrile) as initiator.