Piperidones synthesis

To a large extent the substitution pattern of the amine is variable (24, 52-54). There are more restrictions for the aldehyde component. For the piperidone synthesis, most five- or six-ring aromatic or heteroaromatic aldehydes, as well as their ring-substituted derivatives, can be used (53, 55-57), but so far only a few aliphatic mono- and dialdehydes (e.g., formaldehyde, acetaldehyde, isobutyr-, glutar-, and succinaldehyde) have found their way into the bispidine preparation. 

This reaction is related to the Guareschi-Thorpe Pyridine Synthesis, Chichibabin Pyridine Synthesis, KrOhnke Pyridine Synthesis, and Petrenko-Kritschenko Piperidone Synthesis. 

This reaction was first reported by Petrenko-Kritschenko in 1906. It is the preparation of piperidone via a double Mannich Reaction from acetonedicarboxylic ester, two equivalents of aldehyde, and ammonia (or a primary amine), and is known as the Petrenko-Kritschenko piperidone synthesis. In this reaction, the mixture of reaction components is usually refluxed in an aqueous or alcoholic solution, and the resulting product is difficult to purify. It has been found that the addition of acid to the reaction medium is useful for this reaction.2... 

Other references related to the Petrenko-Kritschenko piperidone synthesis are cited in the literature. ... 

This reaction is related to the Petrenko-Kritschenko Piperidone Synthesis. 

Petrenko-Kritschenko Piperidone Synthesis Pfau-Plattner Azulene Synthesis Pfitzinger Reaction PFitzner-Moffatt Oxidation... 

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