Triphenylphosphine → [(S)-2-(2,6-Difluoro-3-nitrophenoxy)-1-methylethyl]carbamic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

Diethylazodicarboxylate (349 μL, 2.22 mmol) in THF (1 mL) was added slowly to a solution of 2,6-difluoro-3-nitrophenol (260 mg, 1.48 mmol), ((S)-2-hydroxy-1-methylethyl)carbamic acid tert-butyl ester (312 mg, 1.78 mmol) and triphenylphosphine (582 mg, 2.22 mmol) in THF (10 mL) at 0° C. The solution was stirred for 30 min at 0° C., and then concentrated in vacuo. The residue was purified by flash chromatography (Si—PPC, gradient 0-30% EtOAc in cyclohexane) to afford the title compound as a pale yellow oil (340 mg, 69%). 1H NMR (CDCl3, 300 MHz): δ 7.82 (1H, ddd, J=13.0, 9.5, 5.3 Hz), 7.04 (1H, app. td, J=9.4, 2.1 Hz), 4.75 (1H, br s), 4.24-4.12 (2H, m), 4.00 (1H, br s), 1.44 (9H, s), 1.34 (3H, d, J=6.9 Hz)

Provenance & Evidence