Boron tribromide → HCID 54456143, compound

Participants

Reaction Conditions

Reaction Steps

A solution of boron tribromide in CH2Cl2 (1.0 M, 160 mL, 160 mmol) was added dropwise over 30 min to a solution of methyl (S)-8-methoxy-3-oxo-2-(4-trifluoromethylbenzyl)-2,3,4,5-tetrahydro-1H-2-benzazepine-4-acetate (16.67 g, 39.6 mmol) in anhydrous CH2Cl2 (150 mL) at −20° C. under argon. After an additional 1.5 hr at −15 to −20° C., the reaction was recooled to −20° C. and quenched by careful dropwise addition of MeOH (160 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×). Purification by flash chromatography on silica gel (50 to 100% ethyl acetate/hexanes) gave the title compound (14.87 g, 92%) as a white solid: [α]D −81.8° (c, 1.0, MeOH); TLC (silica, 50% EtOAc/hexane) Rf 0.54; MS (ES) m/e 408.2 (M+H)+; 1H NMR (400, CDCl3+2% DMSO-d6) δ 7.53 (d, J=8.1 Hz, 2H), 7.31 (d, J=8.1 Hz, 2H), 6.93 (d, J=8.4 Hz, 1H), 6.70 (dd, 1H), 6.41 (d, J=2.3 Hz, 1H), 5.16 (d, J=16.4 Hz, 1H), 5.01 (d, J=15.6 Hz, 1H), 4.39 (d, J=15.6 Hz, 1H), 3.84 (m, 1H), 3.73 (d, J=16.4 Hz, 1H), 3.71 (s, 3H), 3.01 (dd, 1H), 2.98 (m, 1H), 2.90 (dd, 1H), 2.47 (dd, 1H).

Provenance & Evidence