Synthesis of some new 1,2,4-triazoles starting from isonicotinic acid hydrazide and evaluation of their antimicrobial activities.
5-Pyridin-4-yl-1,3,4-oxadiazole-2-thiol (2) was obtained from the reaction of isonicotinic acid hydrazide with carbon disulfide in basic media and converted into 4-amino-5-pyridin-4-yl-4H-1,2,4-triazole-3-thiol (5) by the treatment with hydrazine hydrate. The synthesis of 3 and 6 was performed from the reaction of 2 and 5 with ethyl bromide. The treatment of 5 with 4-fluorobenzaldehyde or indol-3-carbaldehyde resulted in the formation of 4-[(arylmethylene)amino]-5-pyridin-4-yl-4H-1,2,4-triazole-3-thiols (7a and 7b). The reactions of 2, 5 and 7a with some primary and secondary amines in the presence of formaldehyde afforded the corresponding Mannich bases, 4a, 4b, 9a-9c and 8. All newly synthesized compounds were screened for their antimicrobial activity. The antimicrobial activity study revealed that all the compounds screened showed good or moderate activity except compounds 2, 7a, 7b, 8 and 9b.
Bayrak
Hacer
H
Department of Chemistry, Karadeniz Technical University, 61080 Trabzon, Turkey.
Demirbas
Ahmet
A
Demirbas
Neslihan
N
Karaoglu
Sengül Alpay
SA
D000890:Anti-Infective Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D007538:Isoniazid / Q000031:analogs & derivatives*; D008352:Mannich Bases; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D010069:Oxadiazoles / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship; D014230:Triazoles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D015003:Yeasts / Q000187:drug effects
D000890:Anti-Infective Agents; D008352:Mannich Bases; D010069:Oxadiazoles; D014230:Triazoles; C045575:1,2,4-triazole; D007538:Isoniazid