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

Participants

Reaction Conditions

Reaction Steps

Diethylazodicarboxylate (328 μL, 2.09 mmol) in THF (1 mL) was added slowly to a solution of 2,6-difluoro-3-nitrophenol (243 mg, 1.39 mmol), ((R)-2-hydroxy-1-methyl-ethyl)carbamic acid tert-butyl ester (292 mg, 1.67 mmol) and triphenylphosphine (547 mg, 2.09 mmol) in THF (10 mL) at 0° C. The solution was stirred for 30 min at 0° C., 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 (333 mg, 72%). 1H NMR (CDCl3, 300 MHz): δ 7.82 (1H, ddd, J=13.0, 9.4, 5.3 Hz), 7.04 (1H, app. td, J=9.4, 2.2 Hz), 4.76 (1H, br s), 4.23-4.12 (2H, m), 4.07-3.95 (1H, m), 1.44 (9H, s), 1.34 (3H, d, J=6.8 Hz)

Provenance & Evidence