mannich-bases and thiosemicarbazide

A fast and efficient synthesis of some 1,4-disubstituted thiosemicarbazide derivatives is described. The reaction of 3-chlorobenzoic acid hydrazide with various aryl isothiocyanates gave thiosemicarbazide derivatives (1-11) in good yield. The cyclization of compounds (1-11) in the presence of 2% NaOH resulted in the formation of compounds (12-22) containing the 1,2,4-triazole ring. A series of new Mannich bases (23-33) related to the structure of 1,2,4-triazole has been also synthesized. All of these compounds were tested for their in vitro antibacterial activity against the reference strains of aerobic bacteria - 6 Gram-positive and 3 Gram-negative ones; 12 Staphylococcus aureus clinical isolates were also examined. An attempt was made to clarify the influence of the nature/position of substituents on antibacterial activity of compounds described.

Topics: Anti-Bacterial Agents; Bacteria; Humans; Mannich Bases; Microbial Sensitivity Tests; Semicarbazides; Triazoles

Isatin, its 5-chloro and 5-bromo derivatives have been reacted with N-[4-(4'-chlorophenyl)thiazol-2-yl] thiosemicarbazide to form Schiff bases and the N-Mannich bases of these compounds were synthesized by reacting them with formaldehyde and three secondary amines. Their chemical structures have been confirmed by means of IR, 1H-NMR data and by elemental analysis. Investigation of antimicrobial activity of compounds was done by agar dilution method against 28 pathogenic bacteria, 8 pathogenic fungi and anti-HIV activity against replication of HIV-1 (IIIB) in MT-4 cells. Among the compounds tested 1-[N,N-dimethylaminomethyl]-5-bromo isatin-3-{1'-[4"-(p-chlorophenyl) thiazol-2"-yl] thio semicarbazone} 10 showed the most favourable antimicrobial activity.

Topics: Anti-Bacterial Agents; Anti-HIV Agents; Anti-Infective Agents; Antifungal Agents; Bacteria; Cells, Cultured; Cryptococcus; HIV-1; Humans; Isatin; Mannich Bases; Microbial Sensitivity Tests; Schiff Bases; Semicarbazides