Tetrahydrofuran → Methyl 2,4-diethylbenzoate
Reaction equation
[CH3:1][CH2:2][Mg+].[Br-].Br[C:6]1[CH:15]=[C:14](Br)[CH:13]=[CH:12][C:7]=1[C:8]([O:10][CH3:11])=[O:9].[CH2:17]1COC[CH2:18]1>[Zn+2].[Br-].[Br-].C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.Cl[Pd]Cl.[Fe+2]>[CH2:17]([C:6]1[CH:15]=[C:14]([CH2:2][CH3:1])[CH:13]=[CH:12][C:7]=1[C:8]([O:10][CH3:11])=[O:9])[CH3:18]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 2
Procedure
To stirred mixture of ZnBr2 (40.0 g, 176 mmol, 5.44 equiv, 99%) in THF (100 mL) under nitrogen at 0° C. was added dropwise EtMgBr (60 mL, 3 M in THF). After 0.5 h at 0° C., the temperature was lowered to −78° C. and PdCl2(dppf) (3.72 g, 5.03 mmol, 0.16 equiv, 99%) was added followed by the dropwise addition of a solution of methyl 2,4-dibromobenzoate (compound 204.1, 10.0 g, 32.3 mmol, 1.00 equiv, 95%) in THF (200 mL). The reaction was stirred overnight at room temperature, then carefully quenched with water followed by HCl (aq., 1 M). The resulting mixture was extracted with 3×500 mL of ethyl acetate, and the combined organic layers were washed with 3×50 mL of brine, dried over anhydrous sodium sulfate, and concentrated in vacuo. The residue was purified using silica gel column chromatography with ethyl acetate/petroleum ether (1:60) as eluent to furnish 6.30 g (96%) of methyl 2,4-diethylbenzoate as a colorless oil
Workup
- customwas lowered to −78° C.
- stirringThe reaction was stirred overnight at room temperature
- customcarefully quenched with water
- extractionThe resulting mixture was extracted with 3×500 mL of ethyl acetate
- washthe combined organic layers were washed with 3×50 mL of brine
- dry with materialdried over anhydrous sodium sulfate
- concentrationconcentrated in vacuo
- customThe residue was purified
Sources & evidence
- ORD record
- ord-0b2ab243e4264acca9ce72de73be2a21
- Source dataset
- uspto-grants-2014_10
- Patent number
- US08871790B2
Reaction notes
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