4-chlorobenzeneboronic acid (2.05 eq, 2.05 g), N-boc tyramine (1 eq, 6.55 mmol, 1.60 g), cooper(II)-acetate(1.01 eq, 1.20 g) and pyridine (5 eq, 2.64 ml) were dissolved in 70 ml of dry DCM. In the solution were added 4 Å molecular sieves (3 g) and the resulting mixture was stirred at room temperature for 24 hours. The reaction mixture was then filtered over a celite pad, it was diluted with 150 ml of diethyl ether and was subsequently washed with 150 ml of 0.5N HCl water solution, 150 ml of water and 150 ml of brine. The organic phase was dried, the solvent was evaporated and the resulting crude was purified by chromatography on BIOTAGE SP1 purification device using 50 g normal phase silica SNAP column and cyclohexane/EtOAc solvent system (gradient 5-30% of EtOAc in 20 column volumes). Solvent from the gathered fractions of appropriate composition was evaporated and obtained was {2-[4-(4-chloro-phenoxy)-phenyl]-ethyl}-carbamic acid tert-butyl ester (1.7 g, yield=68.14%, purity=94%). MS: [M−H]−=346.13 1H NMR (300 MHz; CDCl3) δ/ppm 1.42 (s, 9H), 2.75 (t, J=7.0 Hz, 2H), 3.35 (m, 2H), 6.87-6.95 (m, 4H), 7.14 (d, J=8.45 Hz, 2H), 7.22-7.28 (m, 2H)
