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A novel synthesis of 2‐aryl‐4‐piperidones by mannich cyclization of iminoketals
Author(s) -
Bosch Joan,
Rubiralta Mario,
Moral Montserrat,
Valls Maria
Publication year - 1983
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570200319
Subject(s) - chemistry , anhydrous , aryl , hydrogen chloride , aldehyde , chloride , organic chemistry , hydrolysis , mannich reaction , condensation , catalysis , physics , thermodynamics , alkyl
2‐Aryl‐4‐piperidones have been synthesized by condensation between an aromatic aldehyde and a β‐aminoketone ethylene ketal, and further cyclization of the resulting iminoketal with dry hydrogen chloride or anhydrous p ‐toluensulfonic acid. Alternatively, reaction of the above iminoketals with methyl fluorosulfonate followed by dry hydrogen chloride treatment and acid hydrolysis gives directly N ‐methyl‐4‐piperidones. The application of these reactions to the synthesis of some 2‐aryl‐3‐acetylpyrrolidine systems is also described.