The pyrazolines have been found to have diverse applications in medicine. They are known to be potent antibiotic or antioxidizing agents. Two types of sydnonyl-substituted α,β-unsaturated ketones were synthesized by the Claisen-Schmidt condensation for the preparation of sydnonyl-substituted pyrazolines. One is the condensation of 3-(4-ethoxyphenyl)-4-formylsydnone (1) with acetone (2a) or acetophenone (2b), and the other is the condensation of 4-acetyl-3-arylsydnones 5 with various aryl aldehydes 6. Finally, 1H-pyrazoline derivatives 8 were synthesized successfully by reacting the appropriate α,β-unsaturated ketone precursors 7 with hydrazine hydrate.
sydnones - 4-acetyl-3-arylsydnones - sydnonyl-substituted α,β-unsaturated ketones - pyrazoles - sydnonyl-substituted pyrazolines
