The condensation of 2-hydroxythiophenol (I) with 2,5-difluoronitrobenzene (II) in the presence of potassium tert-butoxide in DMF afforded 3-fluorophenoxathiin (III), which was oxidized to the sulfone (IV) using H2O2 and trifluoroacetic acid. Displacement of the fluorine atom of (IV) by 1,1,1-trifluoro-2-propanol (V) employing either KH in DMF or NaH in DMA then furnished the title compound.

The condensation of 2-hydroxythiophenol (I) with 2,5-difluoronitro-benzene (II) in the presence of potassium tert-butoxide in DMF afforded 3-fluorophenoxathiin (III), which was oxidized to the sulfone (IV) using H2O2 and trifluoroacetic acid. Displacement of the fluorine atom of (IV) by 2,2,2-trifluoroethanol (V) employing either KH in DMF or KOt-Bu in acetonitrile then furnished the title compound.

The condensation of 2-hydroxythiophenol (I) with 2,5-difluoronitro-benzene (II) in the presence of potassium tert-butoxide in DMF afforded 3-fluorophenoxathiin (III), which was oxidized to the sulfone (IV) using H2O2 and trifluoroacetic acid. Displacement of the fluorine atom of (IV) by 1,1,3,3-tetrafluoro-2-propanol (V) employing either KH in DMF or KOt-Bu in acetonitrile then furnished the title compound.