Condensation of benzoyl chloride (I) with ammonium thiocyanate in boiling acetone produces benzoyl isothiocyanate (II). This is then coupled with the known 3-amino-5-phenyl-1,2,4-thiadiazole (III) to afford the N-benzoyl thiourea (IV) (1). Finally, hydrolysis of (IV) under alkaline conditions gives rise to the target thiadiazolyl thiourea
In a similar method, 3-amino-5-phenyl-1,2,4-tiadiazole (I) is coupled with ethoxycarbonyl isothiocyanate to give the N-(ethoxycarbonyl)thiourea (II), which is then hydrolyzed to the title compound under alkaline conditions