PROCEDURE FOR FRAMSTAELLNING AV 1,2,3-THIADIAZOLE-5-YLKARBAMIDER

摘要

1,2,3-Thiadiazol-5-yl ureas of the formula:- IMAGE wherein R1 represents hydrogen or alkyl optionally interrupted by one or more oxygen and/or sulphur atoms, and R2 represents alkyl optionally interrupted by one or more oxygen and/or sulphur atoms, or a cycloalkyl radical optionally substituted by one or more alkyl radicals, an aromatic hydrocarbon radical optionally substituted by one or more substituents selected from alkyl, halogen, alkylthio, alkoxy, trifluoromethyl and nitro, or an optionally substituted N-containing heterocyclic radical or NR1R2 represents morpholino, piperidino or pyrrolidino, are prepared by reacting a compounds:- IMAGE with amines (R1-NH-R2) in inert organic solvents. Preferably the compound II is formed in the reaction mixture. The process of the invention makes it possible to prepare the ureas in a safe and technically simple manner in virtually quantitative yields and good purity. Previously the preparations required the use of 5-amino-1,2,3- thiadiazole which is not easily obtained and is not completely harmless.