Summary
Pyrolysis and photolysis of 2-amino-3,5-dicyano-6-phenyl-4H-pyran (1) afford HNCO, acrylonitrile, cinnamonitrile, and 2-hydroxy-3,5-dicyano-6-phenylpyridine. Pyrolysis of 2-carboxyimino-3,5-dicyano-6-phenyl-4H-pyran (2) gives HCN, acrylonitrile, cinnamonitrile and 2-hydroxy-3,5-dicyano-6-phenylpyridine. Furthermore, both pyrolysis and photolysis of 2,6-diamino-3,5-dicyanothiopyran (3a) gives rise to HNCS, acrylonitrile and 6-amino-3,5-dicyano-6-mercaptopyridin. Moreover, comparative studies of pyrolysis and photolysis of 2,6-dicyano-4-arylthiopyran derivatives3b–d revealed similar results. The similarity of products obtained from pyrolysis and photolysis and the mechanistic implications of these data are discussed.
Zusammenfassung
Pyrolyse und Photolyse von 2-Amino-3,5-dicyano-6-phenyl-4H-pyran (1) ergeben HNCO, Acrylnitril, Zimtsäurenitril und 2-Hydroxy-3,5-dicyano-6-phenyl pyridin. Durch Pyrolyse von 2-Carboximino-3,5-dicyano-6-phenyl-4H-pyran (2) entstehen HCN, Acrylnitril, Zimtsäurenitril und 2-Hydroxy-3,5-dicyano-6-phenylpyridin. Weiters resultieren sowohl Photolyse als auch Pyrolyse von 2,6-Diamino-3,5-dicyanithiopyran (3a) in der Bildung von HNCS, Acrylnitril und 6-Amino-3,5-dicyano-6-mercaptopyridin. Vergleichende Untersuchungen zur Pyrolyse und Photolyse von 2,6-Dicyano-4-arylthiopyranderivaten (3b–d) lieferten vergleichbare Ergebnisse. Die Ähnlichkeit der Resultate von Pyrolyse und Photolyse sowie die sich daraus ergebenden mechanistischen Implikationen werden diskutiert.
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Atalla, A.A., Hussein, A.M. & Badr, M.Z.A. Pyrolysis and photolysis processes of pyran and thiopyran derivatives. Monatsh Chem 128, 29–35 (1997). https://doi.org/10.1007/BF00807636
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DOI: https://doi.org/10.1007/BF00807636