Ylide von Heterocyclen, III Pyridinium-Ylide von Malonylheterocyclen
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- Kappe, T., Hariri, M. & Pongratz, E. Monatshefte für Chemie (1981) 112: 1211. doi:10.1007/BF00905476
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Ylides of heterocycles, III. Pyridinium ylides of malonylheterocycles
Reaction of isatoic anhydride with the betaine esters2 or3 represents a new synthesis of pyridinium ylides of type5, which have been previously obtained by several other ways. Treatment of the ylide5 with inorganic acids results in the formation of their pyridinium salts5 a−d. Hydrogenation or dehydrogenation of5 with Pd/C give the piperidylquinoline9 or the betaine10, respectively. Both of them can be prepared by an alternative way. ThepK values of some pyridinium ylides were determined.