Synthesis, characterization, stereochemistry, biological investigation and DNA binding studies on N-acyl-t-3-ethyl-r-2,c-6-bis(4-methoxyphenyl)piperidin-4-ones

Abstract

t-3-Ethyl-r-2,c-6-bis(4-methoxyphenyl)piperidin-4-one (1) and its N-phenylcarbamoyl, N-acetyl and N-chloroacetyl derivatives 2–4, respectively have been synthesized and characterized using IR, 1H, 13C, DEPT-135 & 2D NMR and mass spectral studies. The NMR spectral data indicate that the N-acyl-r-2,c-6-bis(4-methoxyphenyl)piperidin-4-ones 2–4 prefer to exist in a boat conformation B1 with NCO rotational equilibrium. All the compounds show prominent antibacterial activity against the organism S. faecalis and the N-phenylcarbamoyl derivative 2 shows significant activity towards s. paratyphi. Further the compounds 3 &4 are found to be inactive against all the fungal species studied and the compounds 1 &2 show moderate activity against mucor species and A. lipoferum, respectively. The compounds 1–4 show moderate antioxidant activities (DPPH) with standard references viz., Rutin and BHT. Further, the DNA binding studies on these compounds 1–4 have been carried out using Calf Thymus DNA. The compounds 1, 3 &4 possess good binding affinity with DNA. The binding constant for compounds 1, 3 &4 varies in the range of 5.5–0.15 × 104 M−1.