Unexpected transformation of ethyl 1-(4-chlorophenyl)-2-methyl-4-oxo-1,4,5,6-tetrahydropyridine-3-carboxylate and antibacterial activity of the products

Abstract

The cyclization reaction of N-(4-chlorophenyl)-b-alanine, in the presence of piperidine as a catalyst, provided ethyl 1-(4-chlorophenyl)-2-methyl-4-oxo-1,4,5,6-tetrahydropyridine-3-carboxylate, which reactions with different hydrazines were carried out resulting in formation of a variety of tetrahydropyridine, dihydropyrazolone, and oxazole derivatives in good yields. 5-[2-[(4-Chlorophenyl) amino]ethyl]-4-(1-hydrazinylethylidene)-2,4-dihydro-3H-pyrazol-3-one was converted into a series of hydrazones, which provided tetrahydro-3H-pyrazolo[4,3-c]pyridin-3-one under treatment with acids. The structures of all synthesized compounds were confirmed by IR, 1 H NMR, and 13 C NMR spectroscopy. The structures of three compounds were unambiguously assigned by means of X-ray analysis data. Some of the synthesized compounds exhibited weak antibacterial activity.

Tetrahydropyridine: a promising heterocycle for pharmacologically active molecules

“…36 and 21 displayed better activity (MIC = 250 µ g/cm 3 ) against Pseudomonas aeruginosa than 19 (MIC = 500 µ g/cm 3 ) . 37 Sulfoxide derivative of adamantyl THP, N -acetyl-2-(1-adamantyl-sulfoxo)-3-acetoxy-4-phenyl-6hydroxy-1,2,3,6-tetrahydropyridines, was synthesized by Prachayasittikul et al 16,38 Compound 23 presented antibacterial activity against S. pyogenes (IC 50 = 256 µ g/mL) and M. catarrhalis (IC 50 = 256 µ g/mL). The corresponding sulfide derivative of this compounds was inactive as an antimicrobial agent.…”

Synthesis and Heterocyclization of 1‐Aryl‐2‐methyl‐4‐oxo‐1,4,5,6‐tetrahydropyridine‐3‐carboxylates

“…One of the synthesis methods for dihydropyridones involves condensation of β ‐amino acids with ethyl 3‐oxobutanoate in the presence of both acidic and basic catalysts .…”