Reaction Steps
To a solution of the Boc-amine (3, 540 mg, 0.451 mmol) in DCM (250 mL) is added acetic anhydride (0.100 mL, 0.979 mmol), pyridine (1.0 mL, 12.4 mmol) and DMAP (20 mg, 0.169 mmol). The reaction is stirred for 3 h, concentrated directly onto SiO2 and chromatographed (gradient elution: 50-70% EtOAc/hexanes) which provides 465 mg of Boc-amine-acetate (4). 1H NMR (400 MHz, d6-DMSO) δ 10.38 (br s, 1H), 9.20 (br d, 1H), 8.79 (br d, 1H), 8.61 (br d, 1H), 8.56 (s, 1H), 8.44-8.41 (m, 1H), 8.38 (d, 1H), 8.24 (s, 1H), 8.11 (d, 1H), 7.48 (br s, 1H), 7.42 (s, 2H), 7.35-7.29 (m, 6H), 6.14 (s, 1H), 5.47 (t, 1H), 5.31-5.26 (m, 1H), 5.19 (dd, 1H), 4.97 (s, 3H), 4.26 (dd, 1H), 3.72 (dd, 1H), 3.38 (s, 3H), 2.70-2.65 (m, 1H), 2.59 (s, 3H), 2.45 (d, 3H), 2.22-2.14 (m, 1H), 1.96 (s, 3H), 1.57-1.50 (m, 1H), 1.49 (s, 9H), 0.88 (d, 3H), 0.84 (d, 3H). LCMS: Rt=1.81 min, [M+H]+ 1238.
