Synthesis of 2-Amino-5-Substituted-1,3,4-Thiadiazoles (ATDA) and Their Derivatives Using Conventional and Microwave Techniques*


A variety of 2-Amino-5-substituted -1,3,4-thiadiazoles (ATDA) were prepared by the reaction of thiosemicarbazide with different substituted carboxylic acids and phosphorous oxychloride as catalyst using conventional methods in comparison with the advantages of microwave techniques.The 5-(substituted-1,3,4-thiadiazol-2-yl) carbamates derivatives were prepared by refluxing these (ATDA) with ethyl chloroformates using pyridine as a base to neutralize the acid produced which gave higher yield than sodium carbonate. The structures of the products were supported by IR spectroscopy.