Chemical Problems; 2026; V. 24(4); p. 599-608
PREPARATION AND CHARACTERIZATION OF INDOLE-3-CARBALDEHYDE-DERIVED PYRAZOLINE DERIVATIVES AND EVALUATION OF BIOLOGICALEFFICACY
Department of Chemistry, College of Education for Women, Tikrit University, Iraq
E-mail:
ibtahal.saleh23@st.tu.edu.iq
Received Date: 2025-05-14
Accepted Date: 2025-07-28
Keywords:
Heterocyclic, chalcones, pyrazoline, biological activity
Notes:
Abstract: The research involved the preparation of a series of chalcones [I1-I5] by the reaction of indole-3-carbaldehyde with acetophenone substituents in a basic medium. The prepared chalcones were then reacted with aqueous hydrazine in the presence of glacial acetic acid as a catalyst to form the pyrazoline ring [I6-I10]. The prepared compounds were formed using ethanol as the solvent. The products were validated using FT-IR, 1H-NMR, and 13C-NMR spectra, which revealed the formation of the studied reactions. The biological evaluation of the prepared compounds was carried out against two types of bacteria, Gram-negative Escherichia coli and Gram-positive bacteria Staphylococcus aureus, using three different concentrations. The results showed that compounds I9 and I10 exhibited the highest inhibitory activity, with I9 outperforming the standard antibiotic (ciprofloxacin) in terms of the diameter of inhibition, especially at low concentrations (0.001 mg/ml) against E. coli. Compound I10 had the highest activity at high concentrations (0.1 mg/ml) against the same bacteria. Compound I9 had the highest activity against Staphylococcus aureus at high concentrations (0.1 mg/ml), where the high activity was attributed to the presence of (Br) groups in compound I9 and (NO2) groups in compound I10. Compound I5 showed balanced activity against both species, while the other compounds showed limited activity.