Approach to the conversion of 2-(methylthio)-5-(trifluoromethyl)-1,3,4-thiadiazole (TDA) to 2-(methylsulfonyl)-5-(trifluoromethyl)-1,3,4-thiadiazole (TDA sulfone)
AssigneeBayer Aktiengesellschaft
InventorsVidyanatha A. Prasad, Joe J. Hanson, Klaus Jelich
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Abstract
The present invention provides a process for making thiadiazole sulfones. In particular, the present process is used to make 2-(methyl-sulfonyl)-5-(trifluoromethyl)-1,3,4-thiadiazole using catalytic oxidation in the presence of a suitable oxidizing agent. A preferred oxidizing agent is hydrogen peroxide. The catalyst system used for the oxidation reaction is a mixture of boric acid and glacial acetic acid. The molar ratio of glacial acetic acid to 2-(methylthio)-5-(trifluoromethyl)-1,3,4-thiadiazole is from about 0.1:1 to about 0.5:1.
Claims14
A process for making 2-(methylsulfonyl)-5-(trifluoromethyl)-1,3,4-thiadiazole comprising oxidizing 2-(methylthio)-5-(trifluoromethyl)-1,3,4-thiadiazole in a reaction mixture containing an oxidizing agent, boric acid, and glacial acetic acid, to form a reaction product, wherein the molar ratio of glacial acetic acid to 2-(methylthio)5-(trifluoromethyl)-1,3,4-thiadiazole is from about 0.1:1 to about 0.5:1.
Dependencies are inferred from the claim text.