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Synthetic Route to Phenyl Diazenes and Pyridazinium Salts from Phenylazosulfonates

Susanne Gradl, Johannes Köckenberger, Janina Oppl, Martin Schiller and Markus R. Heinrich*

*Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Straße 10, 91058 Erlangen, Germany, Email:

S. Gradl, J. Köckenberger, J. Oppl, M. Schiller, M. R. Heinrich, J. Org. Chem., 2021, 86, 6228-6238.

DOI: 10.1021/acs.joc.1c00013

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The synthesis of pyridazinium salts was achieved from readily available phenylazosulfonates in a single reaction step via the formation of short-lived phenyldiazenes, which undergo a rapid cycloaddition to furans to give the desired products after elimination of water.

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proposed mechanism

Key Words

pyridazines, Diels-Alder cycloaddition

ID: J42-Y2021