Step 1: Synthesis of tert-butyl (racemic)-(1-(4-chlorophenyl)-2-hydroxyethyl)carbamate: (Racemic)-2-amino-2-(4-chlorophenyl)ethanol (2 g, 1.65 mmol, prepared according to the method described in WO2009/47563A1) was dissolved in THF (20 ml), and di-tert-butyl dicarbonate (Boc anhydride. 2.84 ml, 12.24 mmol) and triethylamine (2.436 ml, 17.48 mmol). The reaction mixture was stirred at room temperature and kept overnight. After completion of the reaction, the mixture was concentrated in vacuum and extracted by dilution with ethyl acetate (EtOAc) and 1N hydrochloric acid (HCl). The organic phase was washed with saturated brine, dried over anhydrous sodium sulfate (Na2SO4) and subsequently concentrated in vacuum to give the title compound as a viscous solid (2.8 g, 88% yield).1H NMR (500 MHz, CDCl3) data were as follows: δ 7.34 (2H, m), 7.27 (1H, d), 5.35 (1H, m), 4.75 (1H, m), 4.75 (1H, m). 3.75-3.90 (2H, m), 1.44 (9H, s).
