To a solution of 3-bromo-4-(4-fluorobenzyloxy)pyridine-2(1H)-one (from Step 3, synthesis EXAMPLE 59) (0.2 g, 0.67 mmol) in DMF (11 mL) was added K2CO3 (0.26 g, 1.3 mmol) and 3-(bromomethyl)benzylcarbamic acid tert-butyl ester (0.23 g, 0.80 mmol), and the reaction mixture was stirred at 80° C. for 3 hours. The reaction mixture was cooled to room temperature, and concentrated under reduced pressure. The residue was diluted with a 50% aqueous solution of brine (24 mL), and extracted with CHCL3 (4×50 mL). The combined organics was washed water and then brine, dried (MgSO4), filtered, and concentrated under reduced pressure. Purification by flash column chromatography (silica, 3:7 EtOAc/hexanes) and recrystallization from MeOH afforded {3-[3-bromo-4-(4-fluorobenzyloxy)-2-oxo-2H-pyridin-1-ylmethyl]benzyl}carbamic acid tert-butyl ester as an off-white solid (0.07 g, 20%): mp 136-138° C.; 1H NMR (300 MHz, CDCl3) δ 7.42-7.37 (m, 2H), 7.30-7.20 (m, 5H), 7.08 (t, J=9 Hz, 2H), 6.04 (d, J=9 Hz, 1H), 5.16 (s, 2H), 5.14 (s, 2H), 4.28 (d, J=6 Hz, 1H), 1.44 (s, 9H). ES HRMS m/z 517.1124 (M+H C25H27BrFN2O4 requires 517.1133).
