[CH:1]1([C:4]2[CH:13]=[CH:12][C:7]([C:8]([O:10][CH3:11])=[O:9])=[C:6]([CH2:14][CH3:15])[CH:5]=2)[CH2:3][CH2:2]1.[I:16]I.S(=O)(=O)(O)O>CC(O)=O>[CH:1]1([C:4]2[C:13]([I:16])=[CH:12][C:7]([C:8]([O:10][CH3:11])=[O:9])=[C:6]([CH2:14][CH3:15])[CH:5]=2)[CH2:2][CH2:3]1To a round-bottom flask was added a solution of methyl 4-cyclopropyl-2-ethylbenzoate (compound 226.3, 5.00 g, 24.5 mmol, 1.00 equiv) in AcOH (40 mL). I2 (6.80 g, 26.8 mmol, 1.10 equiv), NaIO4 (2.60 g, 12.2 mmol, 0.50 equiv), and sulfuric acid (400 mg, 4.08 mmol, 0.15 equiv) were added to the reaction. The resulting solution was stirred for 2 h at 50° C. After cooling to ambient temperature, the reaction was carefully quenched with Na2S2O3 (aq., sat.). The mixture was extracted with 2×100 mL of ethyl acetate, and the combined organic layers were dried over sodium sulfate and concentrated in vacuo. The residue was purified using silica gel column chromatography with petroleum ether/ethyl acetate (20:1) as eluent to furnish 4.00 g (49%) of methyl 4-cyclopropyl-2-ethyl-5-iodobenzoate as a yellow oil.
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