Br[C:2]1[CH:11]=[CH:10][C:5]([C:6]([O:8][CH3:9])=[O:7])=[CH:4][C:3]=1[F:12].CN(C=O)C.C(N(CC)CC)C.[CH3:25][O:26][CH2:27][C:28]#[CH:29]>CCOC(C)=O.[Cu]I>[F:12][C:3]1[CH:4]=[C:5]([CH:10]=[CH:11][C:2]=1[C:29]#[C:28][CH2:27][O:26][CH3:25])[C:6]([O:8][CH3:9])=[O:7]
To a mixture of methyl 4-bromo-3-fluoro-benzoate (2.5 g, 10.7 mmol) and copper (I) iodide (204 mg, 1.07 mmol) and palladium dichlorobis(triphenylphosphine) complex (753 mg, 1.07 mmol) under an atmosphere of argon was added DMF (21 mL) and the reaction mixture was cooled to 0° C. Triethylamine (1.95 mL, 13.9 mmol) was added followed by 3-methoxyprop-1-yne (997 μL, 11.8 mmol) and the reaction mixture was stirred at 60° C. for 70 minutes. The reaction mixture was cooled, diluted with EtOAc and filtered over Celite®. The filtrate was washed sequentially with 1 M HCl, 10% NH4OH and brine. The organic layer was separated, dried and concentrated in vacuo and the resulting residue was purified by silica gel column chromatography using EtOAc-hexanes (10-100%) as eluent to give methyl 3-fluoro-4-(3-methoxyprop-1-ynyl)benzoate (1.45 g, 61%). ESI-MS m/z calc. 222.2. Found 223.2 (M+1)+; Retention time: 1.53 minutes (3 min run); 1H NMR (400 MHz, CDCl3) δ 7.75 (ddd, J=11.2, 8.8, 1.5 Hz, 2H), 7.50 (dd, J=7.9, 7.0 Hz, 1H), 4.37 (s, 2H), 3.92 (s, 3H), 3.47 (s, 3H).
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