الفهرس 
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Abstract
The original work of the thesis is subdivided into three main parts : Part 1. Chemical reactivity studies : This part is subdivided into three sections : Section 1.1. Convenient Synthesis of Binary and Fused Pyrazole Ring Systems Binary and fused pyrazole ring systems have been synthesized through treatment of dehydroacetic acid (DHA) 1 with different hydrazines such as 5-hydrazinyl-3-methyl-1H-pyrazole (2) and 2-imino-2H-chromene-3-carbohydrazide (4) afforded the corresponding tetra-binary pyrazole 3 or ’bipyrazole-bis((2-imino-2H-chromen-3-yl)methanone) 5, respectively (Scheme 1). Whereas, treatment of DHA 1 with hydrazine hydrate as a simple hydrazine in dichloromethane as solvent at ambient temperature afforded 7-amino-3,6-dimethyl-1,7-dihydro-4H-pyrazolo[3,4-b]pyridin-4-one (6) at once with excellent yield rather than the diazepin-4-one derivative 6’ (Scheme 3). Section 1.2. Feasible Synthetic Approachs to 4-Hydroxy-2-Pyridinone Systems. A simple approach was applied for the regioselective synthesis of various pyridine-2-one derivatives or annulated pyridine as novel heterocyclic systems from the reaction of dehydroacetic acid (DHA) 1 with mono- or bidentate nucleophiles as well as with benzylamine and/or phenylenediamines in dichloromethane followed by transformation with different halo-compounds in refluxing 1,4-dioxane has been achieved in moderate to excellent yields. Stirring of DHA 1 with benzyl amine in dichloromethane as a weak polar organic solvent at room temperature for 6 h produced 3-acetyl-pyridin-2-one 23 instead of Schiff base 23’ (Scheme 11). Section 1.3. Oriented Synthesis of Bicyclic Pyranone (6/6) Systems and Their Annulated Compounds : The reaction of DHA 1 with malononitrile in refluxing ethanol containing few drops of triethylamine (TEA) afforded two products 36a and fused bicyclic (6/6) framework 36b (Scheme 17). Refluxing of DHA 1 with pyrazolone 37 afforded fused tricyclic system of trimethyl-1-phenyl-1,9a-dihydro-pyrano[3\,4\:5,6]pyrano[2,3-c]pyrazol-5-one 38 (Scheme 17). While, treatment of DHA 1 with acetylacetone in refluxing ethanol containing few drops of TEA afforded 4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl))pentan-2,4-dione 39. Part 2. Geometrical optimization and molecular docking: Geometrical optimization of the molecular structures for the different compounds which is a compelling protocol for interpreting their stabilities and calculating many structural parameters for these compounds was carried out using (B3LYP) exchange functional in the presence of density functional theory (DFT). Part 3. Biological Evaluation. The newly synthesized target compounds were evaluated for their in vitro antioxidant, hepatocellular carcinoma (HepG-2), breast cancer cell line (MCF-7) and human prostate cancer (PC-3). The results showed that the most of compounds have range from moderate to excellent antioxidant and anticancer activities.