Synthesis, characterization and antibacterial activity of some novel thiosemicarbazides, 1,2,4-triazol-3-thiols and their S-substituted derivatives

The thiosemicarbazides 3a-c were appeared by reaction of the corresponding substituted hydrazides 1a-c with allylisothiocyanate 2. Synthesis of some novel 1,2,4-triazole-thiols 4a-c bearing a pyridyl unit using 1-[x-picolinoyl]-4-allyl-thiosemicarbazides [x = 2,3,4] in an alkaline solution, is reported. Also, the S-alkylation of triazole derivatives 5-7a-c is described. The structure of the synthesized compounds resulted from the IR, [1]H and -[13]C NMR spectroscopy and elemental analysis data. The antibacterial studies to all of the synthesized compounds against B. cereus, E. coli, P. aeroginosa, S. aureus and E. faecalis as MIC values are reported. Some of these compounds such as 7a, 4a and 3a exhibited a good to significant antibacterial activity

Simple synthesis and biological evaluation of some benzimidazoles using sodium hexafluroaluminate, Na3AlF6, as an efficient catalyst

Considerable attention has been focused on the synthesis of benzimidazoles due to having a broad spectrum of biological activities such as anti-parasitic, fungicidal, anti-thelemintic and anti-inflammatory activities. As a part of our research work in this area, a series of benzimidasole derivatives [3a-n] were synthesized in good to high yields by reaction of o-phenylenediamine and different aromatic aldehydes in the presence of sodium hexafluroaluminate, Na3AlF6, as an efficient catalyst at 50 degree C. This environmentally benign and practical method offers several advantages, such as high yields, use of available catalyst, mild reaction conditions and easy workup. The antibacterial activity of these benzimidasoles was also evaluated using Staphylococcus aureus [mm] and Escherichia coli [mm] bacterial strain. All synthesized materials were characterized using IR and NMR spectroscopy as well as microanalyses data