Boron tribromide → HCID 54302492, compound

Participants

Reaction Conditions

Reaction Steps

A solution of BBr3 in CH2Cl2 (1.0 M, 60 mL, 60 mmole) was added dropwise over 30 min to a solution of methyl (±)-8-methoxy-3-oxo-2-(2,2,2-trifluoroethyl)-2,3,4,5-tetrahydro-1H-2-benzazepine-4-acetate (5.16 g, 14.94 mmole) in anhydrous CH2Cl2 (60 mL) at −5 to −10° C. under argon. After an additional 1 hr at −5 to −10° C., the reaction was recooled thoroughly to −10° C. and quenched by careful dropwise addition of MeOH (60 mL). The reaction was stirred at −10 to 0° C. for 1 hr, then was concentrated on the rotavap. The residue was reconcentrated from MeOH (2×) then from EtOAc, then was filtered through a pad of silica gel (EtOAc eluent). Concentration of the filtrate left a yellow solid which was triturated with hot hexanes. The title compound (4.74 g, 96%) was obtained as an off-white solid: TLC (1:1 EtOAc/hexanes) Rf 0.40; 1H NMR (400, DMSO-d6) δ 9.28 (s, 1 H), 6.90 (d, J=8.3 Hz, 1 H), 6.62 (dd, J=8.3, 2.5 Hz, 1 H), 6.57 (d, J=2.5 Hz, 1 H), 5.27 (d, J=16.7 Hz, 1 H), 4.22-4.38 (m, 1 H), 4.07-4.22 (m, 1 H), 4.07 (d, J=16.7 Hz, 1 H), 3.72-3.83 (m, 1 H), 3.58 (s, 3 H), 2.94 (dd, J=17.0, 3.8 Hz, 1 H), 2.72 (dd, J=16.7, 9.1 Hz, 1 H), 2.65 (dd, J=17.0, 14 Hz, 1 H), 2.49 (dd, J=16.7, 5.0 Hz, 1 H, partially obscured by residual solvent signal); MS (ES) m/e 354 (M+Na)+.

Provenance & Evidence