13C and 1H nuclear magnetic resonance spectral studies on some 1,4-disubstituted piperazine derivatives

[13]C AND [1]H chemical shifts are reported for a number of 1-[p-substituted phenacyl]-4-arylpiperazine analogues. The present NMR data clearly demonstrate the easy distinction of these analogues utilizing [13] C NMR. A similar differentiation using [1]H NMR was not possible as some of these analogues displayed complex and overlapping proton resonances particularly in the aromatic region. Thus, in the present study emphasis has been given to the [13]C NMR assignments. The methods and techniques followed for the assignments are described

Carbon-13 nuclear magnetic resonance spectra of some 4-substituted analogues of phencyclidine and thienylcyclidine

13C-Chemical shifts are reported for 1-[-1-phenylcylohexyl]-piperidine [PCP], 1-[1-[2-thienyl]cyclohexyl]piperidine [TCP] and a number of related analogues substituted at position 4- of the piperidine ring. Assignments are based on chemical shift theory comparison with related compounds signal multiplicities obtained from the analysis of distortionless enhancement by polarization transfer [DEPT] and attached proton transfer [APT] experiments in addition to 2D-NMR experiments. The substituents exert a similar influence on the piperidine ring carbons in the phenyl and thienyl series of compounds. The present study demonstrstes the value of 13C-NMR in identification purposes