Urea → 2-Tert-butyl-5-nitrophenol

HRID 1465147Notes

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 (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-2fd7bf688edc4f749682b1023a1e0b51
Source dataset: uspto-grants-2015_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08999976B2

Reaction notes

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