Synthesis of new thiophen containing 1,2,4-Triazole-3(5)-one derivatives, characterization and examine of pharmacological properties

In this study, 11 orijinal compounds possessing thiophen-1,2,4-triazole-3(5)-on were synthesized. First step of this study, Ethyl-2-(4-amino-5-oxo-3-(thiophene-2-ylmethyl)-4,5-dihydro-1,2,4-triazole-1-yl) acetate (19) including ester group was obtained. 2-(4-amino-5-oxo-3-(thiophene-2-ylmethyl)-4,5-dihydro-1,2,4-triazole-1-yl)aceto hydrazide(20) named as key compound was performed by using hydrazite hydrat. The treatment of the key compound with various isothiocyanates gave 1-(2-(4-amino-5-oxo-3-(thiophene-2-ylmethyl)-4,5-dihydro-1,2,4-triazole-1-yl)acetyl)-4-substituephenyl thiosemicarbazides (21a-d). The basic treatment of the thiosemicarbazides (21a-d), afforded 4-amino-2-((5-mercapto-4-substitue phenyl-4H-1,2,4-triazole-3-yl)methyl)-5-(thiophene-2-ylmethyl)-2H-1,2,4-triazole-3(4H)ones 5a-d. In the last step of this study, 4-amino-2-((5-(4-florophenylamino)-1,3,4-thiodiazol-2-yl)methyl)-5-(thiophen-2-ylmethyl)-2H-1,2,4-triazole-3(4H)-on was obtained in acidic media via the formation of 1-(2-(4-amino-5-oxo-3-(thiophen-2-ylmethyl)-4,5-dihydro-1,2,4-triazole-1-yl)acetyl)-4-(4-florophenyl) thiosemicarbazite (21c). X-ray data of 19 and 21d compounds was collected and ortep and diagram were presented in the finding section. All compounds were investigated for antioxidant and antimicrobial activity. 21(a-d) compounds involving thiosemicarbazite group were showed highly antioxidant and antimicrobial activity. The structure of 11 new compounds synthesized in this study were analyzed by IR, 1H-NMR, 13C-NMR, MS spectroscopy and reaction mechanisms were proposed for the general methods established in the study.Key Words: Thiophen, 1,2,4-triazole-3(5)-one, thiosemicarbazide, triazole-thiol/thion, thiodiazol, X-ray, antioxidant, antimicrobial activity.