A simplified and efficient bromine-facilitated SF4-preparation method

A novel, simple method for SF4-preparation has escaped discovery over the last 50 years of sulfur–fluorine chemistry and is described in the present study. Sulfur tetrafluoride is readily produced according to the equation:S + (2 + x)Br2 + 4KF → SF4↑ + xBr2 + 4KBrThe reaction is carried out either under autogeneous pressure at ambient or slightly raised temperature in a bomb tube, or in an open system at atmospheric pressure with mild heating and concomitant condensation of the product in a −78 °C cold-trap. Runs from the 5- to the 21-g-scale gave similarly good yields. The new SF4-producing method may be useful for laboratory preparation, and may also represent a new cost-effective alternative for industrial-scale production of this important fluorination reagent.

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