Reaction Steps
To a solution of 107 mg (0.21 mmol) of hydrochloride 31 in 10 mL of methanol is added 1 mL of 1N NaOH. The mixture is stirred for 45 min at ambient temperature, then quenched with 1N KH2PO4 and diluted with ethyl acetate. The organic phase is washed with brine, dried over Na2SO4, filtered and concentrated to a glassy solid. This is dissolved in methanol and treated with ethereal HCl to afford 70 mg (0.14 mmol, 68%) of compound 32 as a white solid: 1H NMR (CDCl3+CD3OD drop) δ 7.69 (s, 1 H), 7.56 (m, 2 H), 7.35 (t, J=8 Hz, 1 H), 6.71 (m, 2 H), 6.63 (m, 1 H), 3.98 (m, 2 H), 2.98 (m, 1 H), 2.8 (m, 1 H), 2.68 (m, 1 H), 2.39 (m, 1 H), 1.92 (s, 3 H), 1.83 (s, 6 H); IR (diffuse reflectance) 3311, 3283, 3257, 3249, 3058, 3007, 2757, 1655, 1646, 1628, 1596, 1551, 1459, 1116, 697 cm−1. MS (CI)m/z(rel intensity) 457 (15), 455 (MH+, 97), 458 (17), 457 (99), 456 (15), 455 (97), 377 (5), 259 (9), 216 (6), 214 (6), 96 (27), 69 (5). HRMS (ESI) calcd for C21H25N2O2F2Br+H1 455.1146, found 455.1145. Anal. Calcd for C21H25BrF2N2O2.HCl+H2O: C, 49.47; H, 5.54; N, 5.49; Found: C, 49.45; H, 5.50; N, 5.54.
