IMPROVED PROCESS FOR THE CONVERSION OF 2-(METHYLTHIMPROVED PROCESS FOR THE CONVERSION OF 2-(METHYLTHIO)-5-(TRIFLUOROMETHYL)-1,3,4-THIADIAZOLE (TDA) TOIO)-5-(TRIFLUOROMETHYL)-1,3,4-THIADIAZOLE (TDA) TO 2-(METHYLSULFONYL)-5-(TRIFLUOROMETHYL)-1,3,4-THIA 2-(METHYLSULFONYL)-5-(TRIFLUOROMETHYL)-1,3,4-THIADIAZOLE (TDA SULFONE) DIAZOLE (TDA SULFONE)

摘要

The present invention provides a process for making thiadiazole sulfones. In particular, the present process is used to make 2-(methylsulfonyl)-5-(trifluoromethyl)-1,3,4-thiadiazole using catalytic oxidation in the presence of a suitable oxidizing agent. The catalyst system used for the oxidation reaction is a mixture of glacial acetic acid and a tungsten catalyst. The tungsten catalyst is preferably selected from the group consisting of sodium tungstate, potassium tunstate, and tungstic acid.