Matrix-assisted laser desorption/ionization and electrospray ionization mass spectrometric study of 2,3-dihydro-1,4-benzoxazepines.
Fragmentations of the protonated adduct ions [M+H](+) of seven 1,4-benzoxazepine derivatives were studied using 'post-source decay' matrix-assisted laser desorption/ionization (PSD MALDI) and electrospray nozzle-skimmer collisionally induced dissociation (ESI-CID) mass spectrometric methods. It was found that both methods generated mainly product ions arising from the cross-ring cleavages of the benzoxazepine ring. Similar product ions were generated under MALDI and ESI conditions; however, it was observed that the loss of the alkylene unit from the N-substituted benzoxazepine, and the loss of a H(2)X molecule (where X = O or S), are more preferred under ESI conditions. Based on the experimental results a mechanism is also proposed for the fragmentation of the oxazepines studied.
Kéki
Sándor
S
Department of Applied Chemistry, University of Debrecen, Hungary.
Nagy
Lajos
L
Deák
György
G
Lévai
Albert
A
Zsuga
Miklós
M