number:
3339
إنجليزية
College:
department:
Degree:
Supervisor:
Assist. Prof. Dr. Firas Abdullah Hassan
year:
2014
- A series of 1,2,4-triazole derivatives were synthesized by cyclization reaction, the benzoic acid hydrazide (1) was synthesized by reaction of methyl benzoate with hydrazine hydrate then compound (1) was reacted with CS2 in solution of alkali ethanol to give potassium dithiocarbazinate salt (2) , the basic nucleus 4-amino-5-phenyl-1-4H-1,2,4-triazole -3-thiol (3) was prepared by cyclization of potassium salt (2) with hydrazine hydrate using water as solvent under reflux condition . compound (3) was subjected to addition reaction with different aromatic aldehydes to synthesize Schiff bases (4a,b) which were cyclized by treating with thioglycolic acid to prepare compounds (5a,b).compounds (6) and (7) obtained by cyclization reaction of compound (3) with urea and thiourea .
- Also in this research, 1,3,4- thiadiazole derivatives were synthesized by cyclization of thiosemicarbazied with substituted carboxylic acid and sulphuric acid, to yield 2-amino-5-R-1,3,4-thiadiazole (8). Schiff bases formation (9a,b) were by reflux of aromatic aldehyde with 2-amino-5-R-1,3,4-thiadiazole (8) in the presence of absolute ethanol. Compounds (10a,b) were prepared by cyclization reaction of compounds (9a,b) with thioglycolic acid.
- The Synthesized compound were confirmed by their melting point ,FTIR ,U.V-visible ,1HNMR spectra and evaluated for their antioxidant activity by using stable free radical 1,1-diphenyl-2-picryl-hydrazyl DPPH. Of all tested compounds. compound (5b) was the most active in all concentrations compared to standard Ascorbic acid with an IC50 value 5.84 μg/ml .
