الفهرس 
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Abstract
Part 1 Design and synthesis of some new heterocyclic compounds The key precursor N-(benzo[d]thiazol-2-yl)carbonohydrazonoyl dicyanide (2) was prepared by diazo-coupling of 2-aminobenzthiazole (1) with malononitrile in pyridine at 0-5 oC. Compound 2 was subjected to react with different secondary amines namely, piperidine, morpholine, piperazine, diphenyl amine, N-methylglucamine and diethanolamine in refluxing ethanol to afford the corresponding 1 : 1 acyclic enaminonitrile adducts 3-8, respectively (Scheme 1). Scheme 1. Synthesis of Enaminonitriles (3-8) Pyrazole 9 was obtained by the reaction of hydrazine hydrate with compound 2 Moreover, compound 2 was reacted with malononitrile in an ethanolic solution in the presence of sodium ethoxide to produce the pyridazine derivative 11 (Scheme 2). Scheme 2. Synthesis of Pyrazole 9 and pyridazine 11 Additionally, in a refluxing ethanolic solution of sodium ethoxide, malononitrile was reacted with compound 7 to form pyrimidine 14 (Scheme 3). Scheme 3. Synthesis of Pyrimidine 14 Compound 15 was produced by heating 7 in a boiling mixture of pyridine and acetic anhydride. Compound 15 was cyclized by heating in DMF catalyzed by TEA for a long-time yielding pyridine derivative 16. In addition, compound 7 was reacted with triethyl orthoformate to afford ethoxymethyleneamino derivative 17. Additionally, it was found that compound 18 was produced by heating a mixture of compound 7 with DMF/DMA (Scheme 4). Scheme 4. Synthesis of Enaminonitrile derivatives 15-18 When compound 7 was refluxed with acid anhydride derivatives such as phthalic anhydride, quinolinic anhydride, pyromeltic anhydride, 1,2,4-benzene tricarboxylic anhydride, 4-nitrophthalic anhydride, 3-nitrophthalic anhydride, and tetrabromophthalic anhydride, the phthalimide derivatives 19–25 were produced, respectively (Schemes 5 and 6). Scheme 5. Synthesis of Imide derivatives 19 and 20 Scheme 6. Synthesis of Imide derivatives 21-25 Compound 26 was produced by fusing the enaminonitrile derivative 7 with the 3,4,9,10-perylenetetracarboxylic dianhydride in the presence of freshly fused sodium acetate (Scheme 7). Scheme 7. Synthesis of Diimide derivatives Part 2 Biological evaluation of the newly synthesized compounds Biological Evaluation Compounds 7 and 8 have been determined to have the strongest antioxidant activity. The effectiveness of the newly synthesized compounds 3, 4, 7, 8, 9, 11, 14–18, and 19–26 was evaluated for their antitumor activities against four cell lines; HepG2, WI–38, VERO, and MCF-7. Additionally, it was found that the two drugs, 14, and 20, exhibit potent efficacy against the four cell lines tested. Molecular docking (PDB=1M17) was used to examine the binding disposition of the docked compounds, in particular 7, 8, 11, and 14, towards the binding site of the EGFR complexed with the co-crystallized ligand. Part 3 Corrosion inhibitors for carbon steel in an acidic environment The corrosion problem is a great problem, which faced the world from the last years until now, we cannot hide this problem from our life but we can reduce “inhibit” it in the metals and alloys by several methods as the environment need. This part discusses the corrosion of carbon steel (CS) in 1 M HCl. The aim of this work contains four main sections. Section 1 : Evaluation of the inhibitor efficiency by weight loss method in the presence and absence of the used organic compounds in 1 M HCl. This revealed that the inhibitor efficiency increases with increasing concentration. These investigated compounds follow Langmuir’s isotherm showing that the inhibition is by adsorption. The degree of surface coverage (θ) for the inhibitors on the metal surface increases with increasing the concentration in the corrosive medium. Section 2 : Potentiodynamic polarization measurements were carried out for CS in 1 M HCl in the absence and presence of different concentrations of the investigated organic compounds. The polarization curves indicated that these inhibitors influence both cathodic and anodic processes (mixed type). AC impedance spectroscopy measurements were carried out for CS in 1 M HCl in the absence and presence of different concentrations of the investigated organic compounds under charge transfer control. The value of charge transfers resistance (Rct) increases with increase in the concentration of the inhibitors and this indicates that the inhibition is due to adsorption of these compounds on CS surface. The order of decreasing the inhibition efficiency of the investigated compounds in 1M HCl solution by all methods were : 1 > 2 >3.