Sulfuric Acid → 2-Bromo-4-tert-butyl-5-nitrophenyl methyl carbonate
Reaction equation
[C:1](=[O:16])([O:14][CH3:15])[O:2][C:3]1[CH:8]=[CH:7][C:6]([C:9]([CH3:12])([CH3:11])[CH3:10])=[CH:5][C:4]=1[Br:13].OS(O)(=O)=O.[N+:22]([O-])([O-:24])=[O:23].[K+]>>[C:1](=[O:16])([O:14][CH3:15])[O:2][C:3]1[CH:8]=[C:7]([N+:22]([O-:24])=[O:23])[C:6]([C:9]([CH3:11])([CH3:12])[CH3:10])=[CH:5][C:4]=1[Br:13]Participants
Conditions
- Temperature
- 0 °C
Procedure
2-Bromo-4-tert-butylphenyl methyl carbonate (5.0 g, 17.4 mmol) was added portion-wise to H2SO4 (9.3 mL, 174.1 mmol) to generate a colorless homogeneous solution. This solution was then cooled to 0° C. and treated with KNO3 (2.1 g, 20.9 mmol) portion-wise maintaining the internal temperature below 5° C. The reaction was stirred for 2 h and then poured on ice water. The aqueous layer was extracted with dichloromethane (3×10 mL). The combined organic extracts was dried over Na2SO4, filtered and concentrated. Purification by silica gel chromatography (10% ethyl acetate/hexane) provided 2-bromo-4-tert-butyl-5-nitrophenyl methyl carbonate (4.4 g, 76% yield). 1H NMR (400.0 MHz, DMSO-d6) δ 7.97 (s, 1H), 7.92 (s, 1H), 3.90 (s, 3H), 1.34 (d, J=5.4 Hz, 9H).
Workup
- temperaturemaintaining the internal temperature below 5° C
- additionpoured on ice water
- extractionThe aqueous layer was extracted with dichloromethane (3×10 mL)
- dry with materialThe combined organic extracts was dried over Na2SO4
- filtrationfiltered
- concentrationconcentrated
- customPurification by silica gel chromatography (10% ethyl acetate/hexane)
Sources & evidence
- ORD record
- ord-3e2fdf4e1ad541c8a7d2d13fc80e101e
- Source dataset
- uspto-grants-2014_01
- Patent number
- US08633189B2
Reaction notes
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