Urea → 2-Tert-butyl-5-nitrophenol

HRID 73967

Reaction equation

[C:1]([C:5]1[CH:11]=[CH:10][C:9]([N+:12]([O-:14])=[O:13])=[CH:8][C:6]=1N)([CH3:4])([CH3:3])[CH3:2].N([O-])=[O:16].[Na+].NC(N)=O.OS(O)(=O)=O.O>OS(O)(=O)=O.O>[C:1]([C:5]1[CH:11]=[CH:10][C:9]([N+:12]([O-:14])=[O:13])=[CH:8][C:6]=1[OH:16])([CH3:4])([CH3:3])[CH3:2]

Participants

Conditions

Temperature: 2.5 °C

Procedure

To a mixture of 2-tert-butyl-5-nitroaniline (1.94 g, 10 mmol) in 40 mL of 15% H2SO4 was added dropwise a solution of NaNO2 (763 mg, 11.0 mmol) in water (3 mL) at 0° C. The resulting mixture was stirred at 0-5° C. for 5 min. Excess NaNO2 was neutralized with urea, then 5 mL of H2SO4—H2O (v/v 1:2) was added and the mixture was refluxed for 5 min. Three additional 5 mL aliquots of H2SO4—H2O (v/v 1:2) were added while heating at reflux. The reaction mixture was cooled to room temperature and extracted with EtOAc twice. The combined organic layers were washed with brine and dried over MgSO4. After removal of solvent, the residue was purified by column chromatography (0-10% EtOAc-Hexane) to give 2-tert-butyl-5-nitrophenol (C-1-a) (1.2 g, 62%). 1H NMR (400 MHz, CDCl3) δ 7.76 (dd, J=8.6, 2.2 Hz, 1H), 7.58 (d, J=2.1 Hz, 1H), 7.43 (d, J=8.6 Hz, 1H), 5.41 (s, 1H), 1.45 (s, 9H); HPLC ret. time 3.46 min, 10-99% CH3CN, 5 min run.

Workup

temperaturethe mixture was refluxed for 5 min
temperaturewhile heating
temperatureat reflux
temperatureThe reaction mixture was cooled to room temperature
extractionextracted with EtOAc twice
washThe combined organic layers were washed with brine
dry with materialdried over MgSO4
customAfter removal of solvent
customthe residue was purified by column chromatography (0-10% EtOAc-Hexane)

Sources & evidence

ORD record: ord-a132ed9a78914d1eaa7166dee7046539
Source dataset: uspto-grants-2014_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08829204B2

Linked notes

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