Studies of rearrangement reactions of protonated and lithium cationized 2-pyrimidinyloxy-N-arylbenzylamine derivatives by MALDI-FT-ICR mass spectrometry.
The rearrangement reactions of protonated and lithium-cationized 2-pyrimidinyloxy-N-arylbenzylamine derivatives were studied by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and infrared multiphoton dissociation mass spectrometry (IRMPD). Our results show that three kinds of rearrangement reactions occur in IRMPD processes. First, nearly all protonated 2-pyrimidinyloxy-N-arylbenzylamine derivatives undergo Pathway A to form the K ion series. It is proposed that this rearrangement (migration of a substituted benzyl group) proceeds by way of a gas-phase intramolecular S(N)2 reaction. Second, a gas phase intramolecular S(N)Ar type rearrangement mechanism is proposed to explain the formation of the F ion series from protonated and lithium-cationized 5 (or 6). This skeletal rearrangement reaction competes with the S(N)2 reaction of the Pathway A, which produces the K ion series, in IRMPD of protonated 5 and 6. Third, the formation pathway of the W ion series is explained by a gas phase Cope type rearrangement mechanism.
Wang
Hao-Yang
HY
Shanghai Mass Spectrometry Center, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, People's Republic of China.
Guo
Yin-Long
YL
Lu
Long
L
D001596:Benzylamines / Q000737:chemistry*; D008094:Lithium / Q000737:chemistry*; D011522:Protons; D011743:Pyrimidines / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation / Q000379:methods*; D017550:Spectroscopy, Fourier Transform Infrared / Q000295:instrumentation / Q000379:methods*
D001596:Benzylamines; D011522:Protons; D011743:Pyrimidines; D008094:Lithium; C030796:benzylamine; C030986:pyrimidine