الفهرس 
ACKNOWLEDGEMENTOnly 14 pages are availabe for public view
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Abstract
”The chief objective of this work is to prepare new chalcophene-based heterocyclic derivatives and evaluating as sensitizers and co-sensitizers for dye-sensitized solar cells (DSSCs), along with cationic furylnicotinamidine derivatives and their antiproliferative activities (NCI, USA). Part I: Synthesis of target dyes HB-1-8. ❖ Synthesis of target dyes HB-1-4: Bifuran structures HB-1-3 (Scheme 1) were prepared via condensation reaction of 2,2’-bifuran-5,5’-dicarbaldehyde (3) with cyanoacetic acid (4), barbituric acid (5a), thiobarbituric acid (5b), in methanol-acetic acid as a solvent with reflux. Dye HB-4 was prepared by refluxing dialdehyde 3 with 4-(2-cyanoacetamido)benzoic acid (6) in ethanol as a solvent and piperidine as a catalyst. The bifuran-dialdehyde 3 was made via a Suzuki coupling reaction of 5-bromofuran-2-carbaldehyde (1) with the (5-formylfuran-2-yl)boronic acid (2).Synthesis of target dyes HB-5-8: The new biphenyl dyes HB-5-8 (Scheme 2) were prepared via condensation reaction of biphenyl-4,4’-dicarbaldehyde (9) with cyanoacetic acid (4), barbituric acid (5a), thiobarbituric acid (5b), in methanol-acetic acid as a solvent with reflux. Dye HB-8 was prepared by refluxing dialdehyde 9 with 4-(2-cyanoacetamido)benzoic acid (6) in ethanol as a solvent and piperidine as a catalyst.<The biphenyl-dialdehyde 9 was made via a Suzuki coupling reaction of 4-<bromobenzaldehyde (7) with the 4-formylphenylboronic acid (8).Part II: Synthesis of target dyes MH-1-10. ❖ Synthesis of target dyes MH-1-3: Symmetric biphenyl structures MH-1, MH-2 (Scheme 3) were synthesized adopting a knoevenagel condensation reaction of [1,1’-biphenyl]- 4,4’-dicarbaldehyde (9) with 2-cyano-N-(4-nitrophenyl)acetamide (10), 2-cyano N-phenylacetamide (11), in absolute ethanol and a catalytic amount of piperidine with reflux. Whereas, MH-3 was obtained by refluxing biphenyl dialdehyde 9 with 1,3-diethyl-2-thiobarbituric acid (12) in methyl alcohol-acetic acid as a solvent.Synthesis of target dyes MH-4-6: The synthesis of symmetric bifuran derivatives MH-4, MH-5 were outlined in Scheme 4 through a knoevenagel condensation reaction of 2,2’- bifuran-5,5’-dicarbaldehyde (3) with 2-cyano-N-(4-nitrophenyl)acetamide (10), 2-cyano-N-phenylacetamide (11), in absolute ethanol with a drops of piperidine with reflux. Whereas, MH-6 was synthesized by treatment of bifuran dialdehyde3 with 1,3-diethyl-2-thiobarbituric acid (12) in methyl alcohol-acetic acid with reflux.Synthesis of target dyes MH-7 & MH-8: The newly unsymmetrical bichalcophene derivatives MH-7 and MH-8 (Scheme 5) were synthesized via a knoevenagel condensation reaction of 5-(5- formylthiophen-2-yl)furan-2-carbaldehyde (14) with 2-cyano-N-(4- nitrophenyl)acetamide (10), 2-cyano-N-phenylacetamide (11), in absolute ethanol and a catalytic drops of piperidine with reflux. Dialdehyde compound 14 was obtained adopting a Suzuki coupling reaction between 5-bromothiophene-2- carbaldehyde (13) and the (5-formylfuran-2-yl)boronic acid (2).Synthesis of target dyes MH-9 & MH-10: Unsymmetrical bichalcophene compounds MH-9 and MH-10 (Scheme 6) were prepared through a knoevenagel condensation reaction of 5-(4- ormylphenyl)thiophene-2-carbaldehyde (15) with 2-cyano-N-(4- nitrophenyl)acetamide (10), 2-cyano-N-phenylacetamide (11), in absolute ethanol and catalytic drops of piperidine with reflux. Dialdehyde compound 15 was synthesized through a Suzuki coupling reaction between 5-bromothiophene- 2-carbaldehyde (13) and 4-formylphenylboronic acid (8).Part III. Synthesis of new dichlorophenylfurylnicotinamidine isomers 19a, b: Synthesis of new dichlorophenylfurylnicotinamidine isomers 19a, b (Scheme 7) was done through a Suzuki reaction of bromo compound 16 with dichlorophenylboronic acids 17 in the presence of Pd(PPh3)4 as a catalyst to furnish furylnicotinonitriles 18a, b. Compounds 18a, b were allowed to react with lithium bis(trimethylsilyl)amide, and subsequent de-protection with HCl(gas)/ethanol. The crude precipitates were neutralized with aq. NaOH (1N) to afford the monoamidine bases. The hydrochloride salts of furylnicotinamidines 19a, b were prepared from the corresponding base of monoamidines by treatment with HCl(gas)/ethanol.”