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 POCl3 or SOCl2. 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. Using the developed approach five, 2-amino-1,3,4-thiadiazoles were synthesized. The structures of all compounds were proven by mass spectrometry, IR, and NMR spectroscopies.

Automated summary

The study aimed to develop a new method for synthesizing 1,3,4-thiadiazol-2-amine derivatives using a one-pot reaction between thiosemicarbazide and carboxylic acid in the presence of polyphosphate ester (PPE). This method avoids the use of toxic additives such as POCl3 or SOCl2 and successfully synthesized five target compounds. The structures of all compounds were confirmed using mass spectrometry, IR, and NMR spectroscopies.