Synthesis and Biological Evaluation of New 1,2,4-Triazolo[1,5-a] pyridine and 1,2,4-Triazolo[1,5-a] isoquinolineDerivatives Bearing Diphenyl Sulfide Moiety as Antimicrobial Agents

Eladasy, Abubaker A; Hussein, Abdelhaleem M; Ishak, Esam A.; Hafiz, Ibrahim S. A.; Gawish, Emad H; Elapasery, Morsy; El-Gaby, Mohamed

doi:10.21608/ejchem.2020.44466.2901

Synthesis and Biological Evaluation of New 1,2,4-Triazolo[1,5-a] pyridine and 1,2,4-Triazolo[1,5-a] isoquinolineDerivatives Bearing Diphenyl Sulfide Moiety as Antimicrobial Agents

Document Type : Original Article

Authors

¹ Department of Chemistry, Faculty of Science, Al-Azhar University, Assiut, Egypt

² Department of Chemistry, Faculty of Science, Al Azhar University, Assiut 71524, Egypt

³ Departmentof Chemistry, Faculty of Science, Al-AzharUniversity at Assiut, Assiut71524, Egypt.

⁴ Department of Chemistry, Faculty of Education, Suez CanalUniversity, Al-Arish, Egypt.

⁵ Dyeing, Printing and Auxiliaries Department, Textile Research Division, National Research Centre, Cairo 12622, Egypt

10.21608/ejchem.2020.44466.2901

Abstract

Hydrazone derivative (3) was used as a precursor for the synthesis of novel [1,2,4]triazolo[1,5-a]pyridine deivatives via its reaction with some electrophilic reagents. Treatment of hydrazone derivative (3) with arylidenemalononitriles(4) in the presence of piperidine afforded the 1,2,4-triazolo[1,5-a]pyridine derivatives (7a-d). Ternary condensation of hydrazone (3), aliphatic aldehyde and malononitrile (1:1:1 molar ratio) in the presence of a basic catalyst furnished the novel 1,2,4-triazolo[1,5-a]pyridine derivatives (8a,b). Similarly, cyclization of hydrazone (3) with ethyl α-cyanocinnamates (9) (1:1 molar ratio) yields the corresponding 1,2,4-triazolo[1,5-a]pyridines (10a-c). The hydrazone (3) can be cyclized with appropriate arylazomalononitriles(11) to afford the corresponding 1,2,4-triazolo[1,5-a]pyridines (14a,b). The behavior of fused thiophene derivative (15) towards electron-poor olefins was investigated. It is has been found that, 1,2,4-triazolo[1,5-a]isoquinoline derivative (17) was obtained by treatment of thiophene derivative (15) with dimethyl acetylenedicarboxylate (DMAD). Condensation of compound (15) with N-phenylmalemide furnished pyrrolotriazoloisoquinoline derivative (18). Also, the triazoloisoquinoline derivative (19) was obtained by condensation of compound (15) with chalcone. All the newly synthesized compounds were characterized by analytical and spectral data and evaluated for their antibacterial and antifungal activities in vitro against two Gram-positive bacteria, two Gram negative bacteria as well as two fungi. In general, the newly synthesized compounds showed good antimicrobial activities.

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