The mass spectra of some phenyl pyridyl ketones

The mass spectra of phenyl 2‐pyridyl, phenyl 3‐methoxy‐2‐pyridyl, phenyl 4‐methoxy‐2‐pyridyl, phenyl 5‐methoxy‐2‐pyridyl, phenyl 6‐methoxy‐2‐pyridyl ketones, phenyl 3‐pyridyl and phenyl 6‐methoxy‐3‐pyridyl ketones, and phenyl 4‐pyridyl ketone were studied. The major fragmentation pathway of all the ketones results in the formation of[C6H5CO]+ and [C5H4NCO]+ type ions. Another fragmentation path is the loss of carbon monoxide with formation of an [M  CO]+ ion after skeletal rearrangement.