Our site uses cookies to improve your experience. You can find out more about our use of cookies in About Cookies, including instructions on how to turn off cookies if you wish to do so. By continuing to browse this site you agree to us using cookies as described in About Cookies. ... 2-Amino-5-alkyl and 2-amino-5-aryl-1,3,4-thiadiazoles were prepared by the dehydration of 2-acylthiosemicarbazides with molar equivalents of methanesulfonic acid in refluxing ...