A Novel Approach to the Synthesis of 1,3,4-Thiadiazole-2-amine Derivatives.

The main purpose of the study was the development of a new method for synthesis of 1,3,4-thiadiazol-2-amine derivatives in a one-pot manner using the reaction between a thiosemicarbazide and carboxylic acid without toxic additives such as POCl or SOCl. The reaction was investigated in the presence of polyphosphate ester (PPE). It was found that, in the presence of PPE, the reaction between the thiosemicarbazide and carboxylic acid proceeds in one-pot through three steps with the formation of corresponding 2-amino-1,3,4-thiadiazole.

Iso-octenidine: Promising Octenidine Analogue with Improved Solubility.

Iso-octenidine, an isomer of octenidine dihydrochloride, was synthesized and studied for the first time. Iso-octenidine was demonstrated to be 3-fold more soluble in water in comparison to original octenidine, and both substances had remarkably similar antibacterial activity (tested on Escherichia Coli and Micrococcus luteus).