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Updated: May 2, 2026

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
Generation and characterization of a 4π-electron three-membered ring 1H-diazirine: An elusive intermediate in nitrile
Cláudio M Nunes1, Cuauhtémoc Araujo-Andrade, Rui Fausto
1Department of Chemistry, University of Coimbra , 3004-535 Coimbra, Portugal.
Abstract:
The photolysis at 222 nm of 5-methyltetrazole isolated in a cryogenic argon matrix leads to formation of methyl nitrile imine as primary product. Subsequent irradiation at 328 nm induces transformation of the nitrile imine into 4π-electron three-membered-ring 3-methyl-1H-diazirine, which photorearranges to give methyl carbodiimide. These products were characterized by IR spectroscopy and theoretical calculations. For the first time, a 1H-diazirine was captured as intermediate in the photoisomerization of nitrile imines into carbodiimides.
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