Methanol → Methyl 2-bromo-5-methylbenzoate
Reaction equation
[Br:1][C:2]1[CH:10]=[CH:9][C:8]([CH3:11])=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].[C:12](Cl)(=O)C(Cl)=O.CO.C([O-])([O-])=O.[Na+].[Na+]>C(Cl)Cl.CN(C=O)C>[Br:1][C:2]1[CH:10]=[CH:9][C:8]([CH3:11])=[CH:7][C:3]=1[C:4]([O:6][CH3:12])=[O:5]Participants
Procedure
To a solution of 2-bromo-5-methylbenzoic acid (215 mg, 1.0 mmol) in DCM (4 mL) and DMF (1 drop) at 0° C. was slowly added oxalyl chloride (0.13 mL, 1.5 mmol). The reaction mixture was stirred at rt for 1 h and to it was added additional oxalyl chloride (0.13 mL, 1.5 mmol). The reaction mixture was stirred for 1 h, added with MeOH (2 mL) and stirred for 6 h. The mixture was treated with Na2CO3 to pH of 9 and extracted with DCM (2×10 mL). The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by column chromatography over silica gel eluted with PE-EA (15:1) to give methyl 2-bromo-5-methylbenzoate (210 mg; yield 92%) as colorless oil. 1H NMR (400 MHz, CDCl3): δ 7.60 (d, J=1.6 Hz, 1 H), 7.53 (d, J=8.8 Hz, 1 H), 7.15 (q, J=3.2 Hz, 1H), 3.92 (s, 3 H), 2.33 (s, 3 H) ppm.
Workup
- customat 0° C.
- stirringThe reaction mixture was stirred for 1 h
- stirringstirred for 6 h
- extractionextracted with DCM (2×10 mL)
- washThe combined organic layers were washed with brine
- dry with materialdried over Na2SO4
- filtrationfiltered
- concentrationconcentrated under reduced pressure
- customThe residue was purified by column chromatography over silica gel
- washeluted with PE-EA (15:1)
Sources & evidence
- ORD record
- ord-1af6c0e441b84788a2aea18515a02ad9
- Source dataset
- uspto-grants-2014_10
- Patent number
- US08853186B2
Reaction notes
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