Synthesis of five-membered heterocyclic rings from chalcone derivatives and evaluation of their biological activity

Bekhal Omer Mohammed *

Department of Chemistry, College of Science, University of Kirkuk, Kirkuk, Iraq
 
Research Article
World Journal of Chemical and Pharmaceutical Sciences, 2026, 08(02), 004-015.
Article DOI: 10.53346/wjcps.2026.8.2.0017
Publication history: 
Received on 19 April 2026; revised on 29 May 2026; accepted on 01 June 2026
 
Abstract: 
A series of aminochalcone and isoxazoline derivatives were synthesized and characterized using spectroscopic methods. The aminochalcones (C1,C2) were prepared through Claisen–Schmidt condensation of 4-aminoacetophenone with 4-nitrobenzaldehyde or 4-chlorobenzaldehyde in alkaline ethanolic medium. The obtained chalcones were then cyclized with hydroxylamine hydrochloride in the presence of sodium hydroxide to afford the corresponding 4,5-dihydroisoxazoline derivatives (I1,I2). The structures of the synthesized compounds were confirmed by melting points, FTIR, UV-Vis, and selected ¹H NMR spectral data. The FTIR spectra of chalcones showed characteristic absorption bands for NH₂, C=O, and C=C groups, while the isoxazoline derivatives showed disappearance of the chalcone carbonyl and olefinic bands with the appearance of new C=N and cyclic C–O absorption bands. These spectral changes confirmed successful cyclization of the chalcone system into the isoxazoline ring.
 
Keywords: 
Chalcone; Isoxazoline; Claisen–Schmidt Condensation; Hydroxylamine Hydrochloride
 
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