13245-77-7

Upstream product

• 39653-65-1 1-methyl-2,6-diphenyl-piperidin-4-one 
• 5554-55-2 2,6-diphenyl-4-piperidone 
• 100-52-7 benzaldehyde 

Downstream Products

• 904243-21-6 1-methyl-2,6-diphenylpiperidin-4-one-O-benzyloxime 
• 39653-65-1 1-methyl-2,6-diphenyl-piperidin-4-one 

Relevant academic research and scientific papers

Convenient synthesis and NMR spectral studies of variously substituted N-methylpiperidin-4-one-O-benzyloximes

A series of variously substituted N-methylpiperidin-4-one-O-benzyloximes were synthesized by three different methods. Among them, the direct conversion of 2,6-diarylpiperidin-4-ones into the corresponding oxime ethers (method A) was proved to be better than the other two methods in the sense of good yield, convenience, easy work-up and quick reaction time. All the synthesized compounds are characterized by IR, Mass and NMR (1H NMR, 13C NMR, 1H-1H COSY, 1H-13C COSY and HMBC) spectral studies. The conformational preference of the synthesized oxime ethers with/without alkyl and aryl substituents at C-3/C-5 and C-2/C-6 is discussed using the spectral data. The observed chemical shifts and coupling constants suggest that the synthesized oxime ethers adopt chair conformation with equatorial orientation of all the substituents, whereas 1-methyl-3-isopropyl-2, 6-diphenylpiperidin-4-one-O-benzyloxime also exists in boat conformation. Based on the NMR data, the effects of oximination on ring carbons and their associated protons and alkyl substituents are discussed. In addition, the effect of NMe group on the 2,6-diarylpiperidin-4-one-O-benzyloximes was also studied.

Synthesis, stereochemistry, and?antimicrobial evaluation of?substituted piperidin-4-one?oxime ethers

In a wide search program toward new and efficient antimicrobial agents, a series of substituted piperidin-4-one oxime ethers (5a-5k) was synthesized and tested for their in vitro antibacterial and antifungal activities. Also, the structures of these oxime ethers and their relative stereochemistries have been investigated by nuclear magnetic resonance spectroscopy. In all the oxime ethers synthesized, the orientation of the N-O bond of the oxime ether moiety syn to C-5 (E-isomer) was deduced based on 1H NMR and 13C NMR spectra. It was found that the sterically less hindered compounds, either C-3 (H) and C-5 (H)- or C-3 (Me) and C-5 (H) -substituted ones 5a, 5c, 5d, 5f, 5g, 5i and 5j prefer chair conformation, whereas the sterically more hindered C-3 (Me) and C-5 (Me) -substituted ones 5b, 5e, 5h, and 5k prefer twist-boat conformation. Among the oxime ethers tested, 1,3,5-trimethyl-2,6-diphenylpiperidin-4-one O-(2-chlorophenylmethyl)oxime (5h) exhibited good antibacterial property against Bacillus subtilis, with minimum inhibitory concentration (MIC) closer to that of reference drug, streptomycin. Compounds, 1,3-dimethyl-2,6-diphenylpiperidin-4-one O-(2-chlorophenylmethyl)oxime (5g) and 1,3-dimethyl-2,6-diphenylpiperidin-4-one O-(2-bromophenylmethyl)oxime (5j) showed potent antifungal activity against Aspergillus flavus and Candida-51, respectively. The later compound 5j is more active than the reference drug while the activity of the former one 5g is similar to that of the reference drug, amphotericin B in terms of MIC. The present results may be used as key steps for the construction of novel chemical entities with better pharmacological profiles than standard drugs.