Synthesis and in vitro antimicrobial activities of new (cyano-NNO-azoxy)pyrazole derivatives

The antibacterial and antifungal activity of a series of products, in which the 1,5-dimethyl-4-(cyano-NNO-azoxy)pyrazol-3-yl and 1,3-dimethyl-4-(cyano-NNO-azoxy)pyrazol-5-yl moieties were linked to pyridine, pyrazole, isoxazole, thiophene and the furan ring, were examined. No molecule displayed activity against the Gram-negative bacteria tested. Conversely, some compounds displayed activity against two Staphylococcus aureus strains, including the methicillin resistant strain. All compounds displayed interesting antifungal activity, the most active compound of the series being the thiophene derivative 7a. This compound’s activity against Candida krusei and Candida glabrata (MIC = 0.25 and 0.5 μg/mL, respectively), two fungal species resistant to azoles, is noteworthy. The presence of the cyano function appeared essential for activity.