Methyl iodide → tert-butyl N-[(4-bromophenyl)methyl]-N-methylcarbamate

In a 60-mL vial, tert-butyl-4-bromobenzylcarbamate (1.25 g, 4.37 mmol) was dissolved in DMF (12 mL). To this solution was added Ag2O (4.0 g, 17 mmol) followed by the addition of CH3I (0.68 mL, 11 mmol). The mixture was stirred at 50° C. for 18 hours. The reaction mixture was filtered through a bed of celite and the celite was washed with methanol (2×20 mL) and dichloromethane (2×20 mL). The filtrate was concentrated to remove most of the DMF. The residue was treated with water (50 mL) and a white emulsion formed. This mixture was extracted with ethyl acetate (4×25 mL), dried over Na2SO4, and the solvent was evaporated to yield tert-butyl-4-bromobenzyl(methyl)carbamate (1.3 g, 98%) as a yellow oil. 1H NMR (300 MHz, DMSO-d6) δ 7.53 (d, J=8.1 Hz, 2H), 7.15 (d, J=8.4 Hz, 2H), 4.32 (s, 2H), 2.74 (s, 3H), 1.38 (s, 9H).