The Synthesis and Antibacterial Activities of 2,5-Bis[(3-aryl)-1,2,4-triazolo[3,4-b]-[1,3,4] thiadiazole-6-yl]thiophenes

Abstract

2,5-bis[(3-aryl)-1,2,4-triazolo[3,4-b]-[1,3,4]thiadiazole-6-yl]thiophenes 2 were synthesized in high yields by cyclization of 3-aryl 4-amino-5-mercapto-1,2,4-triazole 1 with thiophene-2,5-dicarboxylic acid in the presence of POCl₃ and tetrabutylammonium iodide as catalyst. The preliminary antibacterial tests showed that most of them were effective against S. aureus, E. coli and B. subtilis. Compounds 2b, 2c, 2d, 2m, 2n, and 2o exhibited promising antibacterial activity. Compounds 2 were screened for their fungicidal activities against Gibberella zeae, Cerospora beticola sacc, Physalospora piricola and Pellicularia sasakii. Compounds 2b, 2c, and 2d showed a high degree of inhibition against Cerospora beticola sacc.

Keywords:

• 2,5-Bis[(3-aryl)-1,2,4-triazolo-[3,4-b]-[1,3,4]thiadiazole-6-yl]thiophenes
• antibacterial activities
• synthesis

Acknowledgments

We gratefully acknowledge financial support of this work by the Natural Science Foundation of Hubei Province Education Committee of China (Project No. D200660001).

Notes

^aPurified yields of 2a– 2o based on thiophene-2,5-dicarboxylic acid.