ABSTRACT
Key compound 2-(4-amino-5-oxo-3-(thiophene-2-ylmethyl)-4,5-dihydro-1,2,4-tiazole-1-yl) acetohydrazide (3) was synthesized by reacting hydrazine hydrate with ethyl-2-(4-amino-5-oxo-3-(thiophene-2-ylmethyl)-4,5-dihydro-1,2,4-tiazole-1yl)acetate (2), obtained in basic media from 4-amino-5-(thiophene-2-ylmethyl)-2H-1,2,4-triazole-3(4H)-one (1). Compound 3 was converted to thiosemicarbazide derivatives (4a-d) and Schiff base derivatives 6a-e and 7a-e. The treatment of compound 4 with NaOH gave 4-amino-2-((4-(4-aryl)-5-mercapto-4H-1,2,4-triazole-3-yl)methyl)-5-(thiophene-2-ylmethyl)-2H-1,2,4-triazole-3(4H)-ones (5a-d). All newly compounds, well characterized by elemental analyses, IR, (1)H NMR, (13)C NMR and mass spectral studies were tested for their antioxidant and antimicrobial activities. Thiosemicarbazide derivatives (4a-d) were highly active in two antioxidant tests with 69.0-88.2% DPPH· scavenging and 503-1257 µM TEAC values, while the others showed lower or no activity. The results of the two antioxidant tests correlated well. Moreover, Thiosemicarbazide derivatives (4a-d) also showed antibacterial activity against Staphylococcus aureus, Bacillus cereus, and Mycobacterium smegmatis. Thiosemicarbazide group deserves attention in the synthesis of bioactive compounds.
Subject(s)
Anti-Bacterial Agents/pharmacology , Antioxidants/pharmacology , Schiff Bases/chemistry , Semicarbazides/chemistry , Sulfhydryl Compounds/chemistry , Thiophenes/pharmacology , Triazoles/chemistry , Triazoles/pharmacology , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/chemistry , Antioxidants/chemical synthesis , Antioxidants/chemistry , Bacillus cereus/drug effects , Dose-Response Relationship, Drug , Microbial Sensitivity Tests , Molecular Structure , Mycobacterium smegmatis/drug effects , Staphylococcus aureus/drug effects , Structure-Activity Relationship , Thiophenes/chemical synthesis , Thiophenes/chemistry , Triazoles/chemical synthesisABSTRACT
The title mol-ecule, C(30)H(24)O(4), lies about an inversion center located at the mid-point of the central C=C bond. The diphenyl-methanone unit adopts an all-trans conformation. The dihedral angle between the adjacent rings is 53.57â (4)°.
ABSTRACT
In the title compound, C(23)H(21)N(3)O, the dihedral angles formed by the mean plane of the triazole ring [maximum deviation = 0.007â (1)â Å] and the three phenyl rings are 51.13â (8), 52.84â (8) and 47.04â (8)°. In the crystal, mol-ecules are linked by weak C-Hâ¯N inter-actions, forming infinite chains propagating along the b-axis direction.
