Electron impact mass spectra of 1a,3-disubstituted 1,1-dichloro-1,1a,2,3-tetrahydroazirino [2,1-d][1,5]benzothiazepines

✍ Scribed by Jiaxi Xu; Ruoxi Lan; Sheng Jin

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 71 KB
• Volume: 13
• Category: Article
• ISSN: 0951-4198
• DOI: 10.1002/(sici)1097-0231(19990730)13:14<1506::aid-rcm676>3.0.co;2-v

✦ Synopsis

The mass spectrometric behaviour of eight 1a,3-disubstituted 1,1-dichloro-1,1a,2,3-tetrahydroazirino[2,1d][1,5]benzothiazepines has been studied with the aid of mass-analyzed ion kinetic energy spectrometry and exact mass measurements under electron impact ionization. All compounds show a tendency to eliminate a chlorine radical from the aziridine ring and then eliminate a neutral propene or substituted/unsubstituted styrene from the thiazepine ring to yield 1,4-benzothiazine ions. They can also lose hydrogen chloride and a chlorine radical, or lose two chlorine atoms, to undergo a ring enlargement rearrangement to produce 1,6benzothiazocine ions, which can further eliminate propyne or phenylacetylene, or small molecular fragments, to yield some abundant fragment ions.