- Flash vacuum pyrolysis of 1,5-benzodiazepines
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Gas-phase pyrolysis of the 2,4-diphenyl- and 2,4-dimethyl-1,5- benzodiazepines 3 and 4 at 800-850 °C gave a range of heterocyclic products (e.g. quinoxalines 8, 10 and 11, indole 9, benzimidazole 5 and pyrazole 7) in low yields. The formation of most products is initiated by cleavage of the 2,3-bond to give a diradical intermediate, though the pyrazole is obtained by a mechanism involving a 1,5-hydrogen shift followed by an unusual ring contraction.
- Despinoy, Christophe,Lloyd, Douglas,McNab, Hamish,Reed, David
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