Heterocyclic polyfluoro-compounds. Part XX. Nucleophilic substitution in perfluoro-(4-phenylpyridine)

Abstract

Reaction of perfluoro-(4-phenylpyridine)(1) with sodium methoxide in methanol gives 3,5,6-trifluoro-2-methoxy-4-pentafluorophenylpyridine and a small amount of 2,3,5,6-tetrafluoro-4-(4-methoxytetrafluorophenyl)pyridine, 3,5,6-trifluoro-2-methoxy-4-(4-methoxytetrafluorophenyl)pyridine, and 3,5-difluoro-2,6-dimethoxy-4-(4-methoxytetrafluorophenyl)pyridine; (ii) with aqueous ammonia gives 2-amino-3,5,6-trifluoro-4-pentafluorophenylpyridine, 2-amino-3,5,6-trifluoro-4-(4-aminotetrafluorophenyl)pyridine, and 2,6-diamino-3,5-difluoro-4-(4-aminotetrafluorophenyl)pyridine; and (iii) with potassium hydroxide in t-butyl alcohol gives 3,5,6-trifluoro-2-hydroxy-4-pentafluorophenylpyridine and 3,5,6-trifluoro-2-hydroxy-4-(4-hydroxytetrafluorophenyl)pyridine. ¹⁹F N.m.r. spectral data for these products are presented.