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

HRID 243219Notes

Reaction equation

HRID 243219 reaction equation
[F:1][C:2]1[C:7]([N+:8]([O-:10])=[O:9])=[CH:6][CH:5]=[C:4]([F:11])[C:3]=1[OH:12].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.[C:32]([O:36][C:37](=[O:42])[NH:38][CH2:39][CH2:40]O)([CH3:35])([CH3:34])[CH3:33].N(C(OCC)=O)=NC(OCC)=O>C1COCC1>[C:32]([O:36][C:37](=[O:42])[NH:38][CH2:39][CH2:40][O:12][C:3]1[C:4]([F:11])=[CH:5][CH:6]=[C:7]([N+:8]([O-:10])=[O:9])[C:2]=1[F:1])([CH3:35])([CH3:34])[CH3:33]

Participants

6

Reactant 4

HCID 11776TriphenylphosphineHCID 220568ethyl N-ethoxycarbonyliminocarbamateHCID 2733206tert-butyl N-(2-hydroxyethyl)carbamateHCID 537967812,6-Difluoro-3-nitrophenol

Product 1

HCID 68157111[2-(2,6-Difluoro-3-nitrophenoxy)ethyl]carbamic acid tert-butyl esterYield 107.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Procedure

To a solution of 2,6-difluoro-3-nitrophenol (248 mg, 1.416 mmol) and triphenylphosphine (558 mg, 2.127 mmol) in THF (10 mL) was added a solution of (2-hydroxyethyl)carbamic acid tert-butyl ester (274 mg, 1.70 mmol) in THF (2 mL). The mixture was cooled in an ice bath and a solution of diethyl azodicarboxylate (372 mg, 2.127 mmol) in THF (2 mL) was added over 5 min. The reaction was removed from the ice bath after 5 min and stirred at RT for 2 h, then concentrated in vacuo. The resulting residue was purified by column chromatography (Si—PCC, eluant 30-40% EtOAc in cyclohexane) affording the title compound as a colourless gum (483 mg, quantitative). 1H NMR (CDCl3, 300 MHz): 7.84 (1H, ddd, J=9.5, 7.8, 5.3 Hz), 7.05 (1H, dt, J=9.9, 2.2 Hz), 5.05 (1H, bs), 4.26 (2H, t, J=5.0 Hz), 3.52 (2H, q, J=5.4 Hz), 1.45 (9H, s)

Workup

  1. temperatureThe mixture was cooled in an ice bath
  2. customThe reaction was removed from the ice bath after 5 min
  3. concentrationconcentrated in vacuo
  4. customThe resulting residue was purified by column chromatography (Si—PCC, eluant 30-40% EtOAc in cyclohexane)

Sources & evidence

ORD record
ord-cd66745f9c2549c7ab5e3de923e87b99
Source dataset
uspto-grants-2014_02
Patent number
US08653089B2

Reaction notes

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