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

HRID 243233Notes

Reaction equation

CCOC(/N=N/C(OCC)=O)=O.[F:13][C:14]1[C:19]([N+:20]([O-:22])=[O:21])=[CH:18][CH:17]=[C:16]([F:23])[C:15]=1[OH:24].[C:25]([O:29][C:30](=[O:36])[NH:31][C@H:32]([CH3:35])[CH2:33]O)([CH3:28])([CH3:27])[CH3:26].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>C1COCC1>[C:25]([O:29][C:30](=[O:36])[NH:31][C@H:32]([CH3:33])[CH2:35][O:24][C:15]1[C:16]([F:23])=[CH:17][CH:18]=[C:19]([N+:20]([O-:22])=[O:21])[C:14]=1[F:13])([CH3:28])([CH3:27])[CH3:26]

Participants

Conditions

Temperature: 0 °C

Procedure

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)

Workup

concentrationconcentrated in vacuo
customThe residue was purified by flash chromatography (Si—PPC, gradient 0-30% EtOAc in cyclohexane)

Sources & evidence

ORD record: ord-6ba14c3aa1b84973a5730b45f00e6cbc
Source dataset: uspto-grants-2014_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08653089B2

Reaction notes

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