Site of gas-phase methylation of l-phenyl-2-aminopropane

✍ Scribed by Herman Zagppey; Roel H. Fokkens; Steen Ingemann; Nico M. M. Nibbering; Helena Florencio

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 572 KB
• Volume: 26
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/oms.1210260610

✦ Synopsis

The regioselectivity of methyl cation transfer from (CH3),F+, (CH3),C1+ and (CH~)JO+ to 1-phenyl-2 aminopropane was studied by Fourier transform ion cyclotron resonance in combination with collisioa-induced dissociation and neutralization-reionization mass spectrometry of the stable [M + CH,] + ions formed in a chemical ionization source. The (CHJ),F+ ion transfers a methyl cation to the NH, group and the pbenyl ring with almost equal probability. Predominant CHJ+ transfer to the NH, group is observed for the (CHJ),CI+ ion whereas the (CH&O+ ion reacts almost exclusively at the amino group. The preference for methylation at NH, is discussed in terms of a lower methyl cation affinity of the phenyl ring than of the amino group and the existence of an energy barrier for methylation of the phenyl moiety.