الفهرس 
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Abstract
Imidazolone moiety is the basic core of many synthetic and natural products which have remarkable biological performance. Imidazolones have been reported as potent analogues of V-RAF murine growth and phosphodiesterase inhibitors. These compounds are also antagonists of some receptors carrying neurokinin-1 and the dopamine receptor. In view of the biological significance of pyrazolyl-imidazolone derivatives, we report in this thesis a simple and novel synthetic routes for the preparation of a series of compounds containing pyrazolyl-imidazolone ring systems in order to assess their capacity as antioxidant agents. The present work is divided into two main sections: Section I: Synthesis of heterocycles incorporated pyrazolyl-imidazolone ring systems. Section II: Biological evaluation of the prepared compounds as antioxidant agents. Section (I)
The synthetic methods implemented to acquire the pyrazolyl-oxazol-5(4H)-one and the pyrazolyl-imidazolones are mentioned in Schemes 1-7. The starting material pyrazolyl-oxazol-5(4H)-one 2 was prepared in good yield in two consequence steps via heating acetophenone with phenyl hydrazine in ethanol to yield 1-phenyl-2-(1-phenylethylidene)-hydrazine, which upon treatment with phosphorus oxychloride in dimethylformamide at 80oC produced the anticipated 1,3-diphenyl-4-formyl-1H-pyrazole (1). The latter product is converted to compound 2 upon heating with benzoylglycine in acetic anhydride having freshly melted sodium acetate (Scheme 1). Section (II)
Antioxidant Activity using ABTS method. The synthesized compounds were screened and evaluated as antioxidant agents using ABTS method, in which L-ascorbic acid was used as a reference. The results showed clearly that compound 25 is the most potent active antioxidant agent compared to the results obtained by vitamin C (positive control) with inhibition % at 66.4%. Compounds 19 and 21-28 displayed remarkable antioxidant activities with inhibition % higher than 50% in the following order: 25 > 24 > 19 > 28 > 27 > 26 > 22 > 21> 23. Further interpretation of the results revealed that, compounds 6, 11, 14-18 and 20 exhibited moderate activities with inhibition % ranges between 30-50%, while compounds 2-5, 7-10, 12 and 13 have the lower activities.