Abstract: | Under electron impact, 3-aryl-4-hydroxyisoquinolines form [M – H]+, [M – CO]+ and [M – H – CO]+ ions with a subsequent elimination of HCN or CH3CN. A cyclic structure for the [M – H]+ ion is suggested. The primary act of fragmentation of the corresponding methyle ether derivatives is the loss of CH3?, as well as H?; the further fragmentatio is similar to that described above. It has been established that the unusual [M – H]+, [M – OH]+ and [M – CH5?]+ ions are formed when 8 fragments. Fragmentation schemes for all compounds are proposed based upon high resolution mass spectra and deuterated analogues. |