A solution of 3.75 g of 4-cyano-2,3-difluorophenyl trifluoromethanesulfonate in 220 mL of dioxane is admixed at ambient temperature with 5 g of N-Boc-4-amino-3-fluorophenylboronic acid, 3.87 g of sodium carbonate in solution with 56 mL of distilled water and then 1.81 g of tetrakistriphenylphosphinepalladium. The reaction mixture is heated for 3 h at reflux and then poured, after cooling, into the distilled water. This mixture is extracted with ethyl acetate, the organic phase is decanted, washed a number of times with distilled water, then with saturated aqueous sodium chloride solution, dried over magnesium sulfate and then concentrated to dryness under reduced pressure. The solid obtained is chromatographed on a silica column (eluent: cyclohexane/ethyl acetate, 90/10 by volume). Evaporation to dryness under reduced pressure of the fractions containing the expected product gives 0.75 g of tert-butyl(4′-cyano-3,2′,3′-trifluorobiphenyl-4-yl)carbamate in the form of a pale pink solid, whose characteristics are as follows:
