Sulfuric Acid → Methyl 5-bromo-2-iodobenzoate

反応式

[I:1][C:2]1[CH:11]=[CH:10][CH:9]=[CH:8][C:3]=1[C:4]([O:6][CH3:7])=[O:5].[Br:12]N1C(=O)CCC1=O.OS(O)(=O)=O>C(O)(=O)C>[Br:12][C:9]1[CH:10]=[CH:11][C:2]([I:1])=[C:3]([CH:8]=1)[C:4]([O:6][CH3:7])=[O:5]

参加物

実験手順

To a stirred slurry of methyl 2-iodo-benzoate (5.0 g, 0.019 mol) and N-bromosuccinimide (3.74 g, 0.021 mol) in acetic acid (10 mL) was added concentrated H2SO4 (10 mL) dropwise, keeping the temperature at 20–40° C. The mixture was stirred at room temperature for 88 hours and then heated at 50° C. for 4 hours. The mixture was cooled to 10° C., treated with 40 g of ice water, and extracted with 50 mL of CH2Cl2. The organic phase was washed in succession with 2×50 mL 5% NaHCO3, 50 mL 10% Na2S2O3, 50 mL water, and concentrated to colorless oil. The residue was purified by column chromatography (silica gel, 10:90 EtOAc:hexane) to provide the title compound. 1H NMR (CDCl3, 400 MHz) δ 7.92 (d, J=4 Hz, 1H), 7.83 (d, J=8 Hz, 1H), 7.27 (dd, J=8, 4 Hz, 1H), 3.92 (s, 3H); MS (DCI/NH3) [M+NH4]+ at 358, [M+NH3—NH4]+ at 375.