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The company's thinking is that just as fluorine or trifluoromethyl groups often confer enhanced activity on drugs or pesticides, so the pentafluorothio group might also be useful.
The company found earlier that direct fluorination of m- or p-nitrothiophenol yields m- or p-nitrophenylsulfur pentafluoride. At the ChemSpec exposition in Lyon, the company said hydrogenation of the m-nitro compound producesm -pentafluorothioaniline in 70% yield, which is converted to the acetanilide with acetic anhydride in 42% yield. Diazotization and treatment of the aniline with potassium iodide gives m-iodophenylsulfur pentafluoride. Palladium-catalyzed coupling of the iodo compound with benzeneboronic acid gives 93% of 3-pentafluorothiobiphenyl and with phenylacetylene gives 24% of the substituted diphenylacetylene.
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