Synthesis, characterization and antimicrobial activity of some new 1-(fluorobenzoyl)-3-(fluorophenyl)thioureas

Synthesis of a variety of new 1-(isomeric fluorobenzoyl)-3-(isomeric fluorophenyl)thioureas (1a–t) was accomplished in two steps. The synthetic route involves the reaction of equimolar quantities of isomeric fluorobenzoyl chlorides with potassium thiocyanate in anhydrous acetone to afford the corresponding isothiocyantes in situ, followed by treatment with equimolar quantities of isomeric fluoroanilines. All of the synthesized compounds (1a–t) were screened for their in vitro antibacterial activity using Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis) and Gram-negative bacteria (Escherichia coli, Pseudomonas aureginosa). The minimum inhibitory concentration (MIC) was also determined for the most active compounds. In vitro antifungal activity was also determined against the five fungal species (Rhizopus oryzae, Aspergillus tereus, Fusarium oxysporum, Aspergillus niger, Aspergillus fumigatus). In general, the antifungal activity of compounds was better than their antibacterial activity.