To a solution of 2-(6-(methoxymethoxy)-2,2,7,8-tetramethylchroman-5-yl)ethanamine (450 mg, 1.8 mmol) in THF (4.2 mL) at 23° C. was added tosyl chloride (390 mg, 2.0 mmol) and pyridine (270 μL, 3.4 mmol). The reaction mixture was stirred at room temperature for 45 min, diluted in 50 mL EtOAc, washed with 1 M aqueous citric acid (2×25 mL) and brine (1×25 mL). The remained organics were dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The residue was purified by silica gel chromatography (gradient elution 5→35% EtOAc/Heptane) to produce 300 mg N-(2-(6-(methoxymethoxy)-2,2,7,8-tetramethylchroman-5-yl)ethyl)-4-methylbenzenesulfonamide. 1H NMR (CDCl3, 400 MHz) 7.48 (d, 2H), 7.09 (m, 8H), 5.20 (s, 1H), 4.82 (s, 2H), 3.55 (s, 3H), 3.10 (q, 2H), 2.70 (t, 2H), 2.45 (t, 2H) 2.35 (s, 3H), 2.11 (s, 3H), 2.04 (s, 3H), 1.65 (t, 2H), 1.20 (s, 6H) ppm.
