Potassium Nitrate → Methyl 4-nitro-2-(trifluoromethoxy)phenyl carbonate
Reaction equation
[C:1](=[O:16])([O:4][C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][C:6]=1[O:11][C:12]([F:15])([F:14])[F:13])[O:2][CH3:3].[N+:17]([O-:20])([O-:19])=[O:18].[K+]>OS(O)(=O)=O>[C:1](=[O:16])([O:4][C:5]1[CH:10]=[C:9]([N+:17]([O-:19])=[O:18])[CH:8]=[CH:7][C:6]=1[O:11][C:12]([F:15])([F:13])[F:14])[O:2][CH3:3].[C:1](=[O:16])([O:4][C:5]1[CH:10]=[CH:9][C:8]([N+:17]([O-:20])=[O:18])=[CH:7][C:6]=1[O:11][C:12]([F:15])([F:13])[F:14])[O:2][CH3:3]Participants
5
Procedure
Methyl 2-(trifluoromethoxy)phenyl carbonate (200 mg, 0.85 mmol) was added portion-wise to H2SO4 (600 μL) at 0° C. to generate a colorless homogeneous solution. KNO3 (103 mg, 1.02 mmol) was added 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 were dried over Na2SO4, filtered and concentrated. Purification by silica gel chromatography (0-10% ethyl acetate/hexanes) provided the two regioisomers methyl 5-nitro-2-(trifluoromethoxy)phenyl carbonate (Isomer A, 120 mg) and methyl 4-nitro-2-(trifluoromethoxy)phenyl carbonate (Isomer B, 75 mg).
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 were dried over Na2SO4
- filtrationfiltered
- concentrationconcentrated
- customPurification by silica gel chromatography (0-10% ethyl acetate/hexanes)
Sources & evidence
- ORD record
- ord-1149e6e164f9410797bf8181fff891e3
- Source dataset
- uspto-grants-2013_02
- Patent number
- US08367660B2
Reaction notes
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