Synthesis, characterization, and biological studies of some novel pyrazole carboxamide, pyridazine and thienopyridazine derivatives

Abstract

The arylhydrazones 3a, b were prepared and reacted with various reagents to yield the target compounds pyrazoles 6a–f, 1,6-dihydropyridazine-3-carboxamide derivatives 9a,b and thieno[3,4-d]pyridazine-1-carboxamide derivatives 10a,b. The structures of the synthesized compounds were confirmed by various spectral data and elemental analyses. Furthermore, all target derivatives were tested for their antibacterial bioactivity against different types of Gram+‏ve and Gram-ve strains and for antifungal activity against two fungi micro-organisms by well diffusion method. Thus, the observed results showed that the 5-cyano-6-imino-N-(4-methoxyphenyl)-4-methyl-1-phenyl-1,6-dihydropyridazine-3-carboxamide (9b) displayed the best antimicrobial activity (with MIC values ranged from 0.49 ± 0.2 to 3.9 ± 0.6 μg/mL).

Graphical Abstract

Keywords:

• Antimicrobial activities
• pyrazoles
• pyridazines
• thieno[34-d]pyridazines