The photo‐initiated substitution reactions of 4‐chloropyridine and the related 1‐(4′‐pyridyl)‐4‐pyridone with benzophenone in aqueous 2‐propanol

4-Chloropyridine (1) converts to 1-(4′-pyridyl)-4-pyridone (4) in aqueous 2-propanol. The photo-initiated reaction of both of these compounds in acidic and non-acidic 4:1 2-propanol/water with and without benzophenone is reported.