Gas‐phase fragmentation of protonated 3‐phenoxy imidazo[1, 2‐a] pyridines using tandem mass spectrometry and computational chemistry. (8th December 2021)

• Record Type: Journal Article
• Authors: Guo, Yanchun; Li, Shigai; Chen, Hong; Wang, Yuexiu; Cao, Shuxia; Zhao, Yufen
• Is Part Of: Journal of mass spectrometry. Volume 56:Number 12(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-12-08
• Subjects: 3‐phenoxy imidazo [1, 2‐a] pyridine -- computational chemistry -- fragmentation mechanism -- radical -- tandem mass spectrometry; Mass spectrometry -- Periodicals; 543.65
• DOI: 10.1002/jms.4794
• Languages: English
• ISSNs: 1076-5174

Abstract

Abstract: Imidazo[1, 2‐a] pyridine is one of the pharmaceutically important scaffolds and has been widely studied due to its extensive biological activities. In this work, electrospray ionization tandem mass spectrometry (ESI‐MS/MS) in positive mode was used to study the gas‐phase fragmentation behavior of a series of 3‐phenoxy imidazo[1, 2‐a] pyridines. Proposed fragmentation pathways were supported by ESI‐MS/MS data and computational thermochemistry. Homolytic cleavage of the 3‐phenoxy C‐O bond was the characteristic fragmentation of 3‐phenoxy imidazo [1, 2‐a] pyridines. The eliminations of the one substituted phenoxy radical and CO produced other diagnostic ions for 3‐phenoxy imidazo [1, 2‐a] pyridines, which were useful to identify the 3‐phenoxy group and imidazo [1, 2‐a] pyridine scaffold. The results contribute to the further understanding of the gas‐phase fragmentation of 3‐phenoxy imidazo [1, 2‐a] pyridines and the identification of other analogs using tandem mass spectrometry techniques.