Methanol → Methyl 4-bromo-2-methylbenzoate
Reaction equation
[Br:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[C:4]([CH3:11])[CH:3]=1.[CH3:12]O>>[Br:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([O:8][CH3:12])=[O:7])=[C:4]([CH3:11])[CH:3]=1Participants
Procedure
To a solution of 4-bromo-2-methylbenzoic acid (5.11 g, 23.8 mmol, 1.0 equiv) in methanol (25 mL) was added dropwise ulfuric acid (2.0 mL) over about 3 minutes (mildly exothermic). The resulting mixture was refluxed for 4 hours. After cooling to room temperature, the reaction mixture was carefully quenched into saturated aqueous NaHCO3 (100 mL) (note—significant gas evolution) and extracted with dichloromethane (200 mL×1 then 50 mL×1). The combined organic phases were washed with a mixture of brine/saturated NaHCO3 (9:1)(50 mL), dried (Na2SO4), and concentrated under reduced pressure to obtain the title compound as a colorless oil (5.28 g, 97%). 1H NMR (400 MHz, CDCl3): δ 7.78 (d, J=8.0 Hz, 1H), 7.42 (d, J=1.6 Hz, 1H), 7.38 (dd, J=1.6 Hz, 1H), 3.89 (s, 3H), 2.58 (s, 3H).
Workup
- temperatureThe resulting mixture was refluxed for 4 hours
- customthe reaction mixture was carefully quenched into saturated aqueous NaHCO3 (100 mL) (note—significant gas evolution)
- extractionextracted with dichloromethane (200 mL×1
- washThe combined organic phases were washed with a mixture of brine/saturated NaHCO3 (9:1)(50 mL)
- dry with materialdried (Na2SO4)
- concentrationconcentrated under reduced pressure
Sources & evidence
- ORD record
- ord-575a2c8dcd3f4fd48ed9cd2fbc740c82
- Source dataset
- uspto-grants-2014_10
- Patent number
- US08871790B2
Reaction notes
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