Tracing of ethyl 2-acetyl-3-(arylamino)butanoate
intermediates (b-amino ketones) and their structural
B. Palakshi Reddy
G. L. Balaji
Received: 24 August 2011 / Accepted: 12 January 2012 / Published online: 26 January 2012
Ó Springer Science+Business Media B.V. 2012
Abstract Tracing of ethyl 2-acetyl-3-(phenylamino)butanoate intermediates
(b-amino ketones) was performed during the course of N-arylpiperidone synthesis
by reaction of aromatic amines, acetaldehyde, and ethyl acetoacetate. The structural
conﬁnement and stereochemistry of these molecules were explained by use of 2D
NMR spectroscopy and X-ray crystallography.
Keywords Mannich condensation Á b-Amino ketones Á
Ethyl 2-acetyl-3-(phenylamino)butanoates Á Intermediates Á Piperidin-4-one
The stereochemistry and synthesis of 2,6-disubstituted piperidin-4-ones have been
of interest since their discovery [1, 2], owing to their biological importance [3, 4].
Prostakov and Gaivoronskaya  have reviewed the importance of piperidin-4-ones
as intermediates in the synthesis of a variety of physiologically active compounds.
Although the synthesis of 2,6-diaryl-substituted piperidin-4-ones has been reported
in the literature, we found no report on N-arylpiperidin-4-one synthesis by reaction
of aromatic amines, acetaldehyde, and ethyl acetoacetate, which is of interest. Most
literature methods for piperidin-4-one synthesis do not discuss intermediate
formation; the obvious importance of this prompted us to study the formation of
intermediates via which differently substituted 4-piperidones can be synthesized.
Electronic supplementary material The online version of this article
(doi:10.1007/s11164-012-0489-x) contains supplementary material, which is available to authorized
K. Rajesh Á B. Palakshi Reddy Á G. L. Balaji Á S. Sarveswari Á V. Vijayakumar (&)
Synthetic Organic Chemistry Research Laboratory, Organic Chemistry Division,
School of Advanced Sciences, VIT University, Vellore 632 014, Tamil Nadu, India
Res Chem Intermed (2012) 38:1629–1635