Conformational analysis of some heterocyclic systems .1.
Conformational analysis of substituted N-phenylcarbamoypiperidin-4-ones
By:Kumar, RK (Kumar, RK); Pillay, MK (Pillay, MK)
INDIAN JOURNAL OF CHEMISTRY SECTION B-ORGANIC CHEMISTRY INCLUDING MEDICINAL
CHEMISTRY
Volume: 35
Issue: 5
Pages: 418-425
Published: MAY 1996
View Journal Information
Abstract
The conformations of variously substituted N-phenylcarbamoylpiperidin-4-ones have been analysed
using IR, H-1 and C-13 NMR data. The spectral data suggest the coplanar orientation of the
phenylcarbamoyl moiety in all the compounds with respect to dynamically averaged plane of the
piperidone ring system. The non-observation of anisochronous signals for the protons/carbons
adjacent to the ring nitrogen, despite the coplanar orientation of the phenylcarbamoyl moiety is related
to the faster rotation around the N-CO bond (i.e., lower activation energy barrier, Delta G#) compared
to the NMR time scale. While the symmetrically substituted compounds viz., 6 and 10 are assumed to
have a sofa conformation, a twist boat conformation is preferred by the other unsymmetrically
substituted piperidones (7,8 and 9). In case of 8, the proposed conformation in solution is further
cooroborated by the solid state conformation derived by X-ray diffraction study. The importance of
A((1,3)) strain indicating the preferred conformations has also been described.
Keywords
KeyWords Plus:BENZOMORPHAN-RELATED-COMPOUNDS; DYNAMIC NMR; 2-ARYL-4PIPERIDONES; ANALGESICS
Author Information
Reprint Address: Kumar, RK (reprint author)
BHARATHIDASAN UNIV,DEPT CHEM,TIRUCHCHIRAPPALLI 620024,INDIA.
Publisher
COUNCIL SCIENTIFIC INDUSTRIAL RESEARCH, PUBL & INFO DIRECTORATE, NEW DELHI
110012, INDIA
Categories / Classification
Research Areas:Chemistry
Web of Science Categories:Chemistry, Organic
Document Information
Document Type:Article
Language:English
Accession Number: WOS:A1996UG52600005
ISSN: 0376-4699
Other Information
IDS Number: UG526
Cited References in Web of Science Core Collection: 29
Times Cited in Web of Science Core Collection: 5