Mass spectral fragmentation of 2a,4‐disubstituted 2,2a,3,4‐tetrahydro‐2‐phenoxy‐1H‐azeto[2,1‐d][1,5]benzothiazepin‐1‐ones under electron impact ionization conditions

Abstract

The mass spectrometric fragmentation of 2a,4-disubstituted 2,2a,3,4-tetrahydro-2-phenoxy-1H-azeto[2,1-d][1,5]benzothiazepin-1-ones has been investigated using the aid of mass-analyzed ion kinetic energy spectrometry. All compounds tend to eliminate a phenoxy, phenol, and phenoxyketene, respectively, from molecular ions. [M(+)-PhO] ions could also form [M(+)-PhOH] ions, which could further lose alkenes. [M(+)-PhOCH=C=O] ions could further yield 2-arylbenzothiazole ions and other fragment ions.

Gas‐phase fragmentation of protonated benzodiazepines

“…MS has superior selectivity and sensitivity than other detection methods; MS evidence is considered to be the most reliable and less likely to be challenged in court 12, 23. While electron ionization is the major ionization technique in GC/MS,24–27 softer ionization techniques, including electrospray ionization (ESI), have been widely used in LC/MS in recent years. For these softer ionization techniques, structural information on the benzodiazepines can be derived from tandem mass spectrometry (MS/MS).…”