Rearrangements in the mass spectra of α-phenylcinnamic acid and its derivatives

✍ Scribed by K. P. Madhusudanan; V. S. Murthy; D. Fraisse; M. Becchi

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 316 KB
• Volume: 26
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/oms.1210260525

✦ Synopsis

The electron impact ionization and collisional activation mass spectra of a-phenylcinnamic acid and its derivatives have been studied. The loss of a phenylic hydrogen is not an important process in these molecules, unlike the unsubstituted cinnamic acids. However, in o-chloro-a-phenylcinnamic acid and its methyl and trimethylsilyl derivatives loss of CI resulting in the formation of 2-substituted-5phenylbenzopyrilium ion is an important fragmentation pathway. The rearrangement ions observed at m/z 118 and 107 in the Spectrum of a-phenylcinnamic acid have been found to bave the structures of the M" of benzofuran and PhCH=bH, respectively. The ion at m/z 121 in the spectrum of the methyl ester of a-phenylcinnamic acid has been found to have the structure PhCH=OMe.