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Microwave-Assisted Preparation of 1-Aryl-1H-pyrazole-5-amines
Published on: June 23, 2019
Enantioseparation and antioxidant activity of novel diarylpyrazoline derivatives
Messaouda Ameur1, Khaled Sekkoum1, Francisco Gonazles2
1Bioactive Molecules and Chiral Separation Laboratory, Faculty of Exact Sciences, University Tahri Mohamed of Bechar, Bechar, Algeria.
Abstract:
Three chiral pyrazoline derivatives were synthesized by a flavanone ring-opening reaction followed by cyclocondensation with hydrazine hydrate to give better yields. Their enantiomeric resolution was achieved using polysaccharide chiral stationary phase columns consisting of cellulose (Chiralcel®OD-RH, Chiralcel®OZ-3) and amylose (Chiralpak®IA) by high-performance liquid chromatography. The separation was affected by the nature and concentration of the alcohol modifiers in the mobile phase. Taking 5-methoxy-2-(3-phenyl-4,5-dihydro-1H-pyrazol-5-yl)phenol (3a) as an example, the best separation was obtained by using the Chiralpak®IA column, with a separation factor α = 1.24 and Rs = 5.66 within an analysis time of <30 min. The diarylpyrazolines showed good antioxidant activity, studied by the DPPH method.
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