[CH:1]1([C:4]2[CH:13]=[CH:12][C:7]([C:8]([O:10][CH3:11])=[O:9])=[C:6]([CH3:14])[CH:5]=2)[CH2:3][CH2:2]1.[I:15]I.S(=O)(=O)(O)O.O>CC(O)=O.C(OCC)(=O)C>[CH:1]1([C:4]2[C:13]([I:15])=[CH:12][C:7]([C:8]([O:10][CH3:11])=[O:9])=[C:6]([CH3:14])[CH:5]=2)[CH2:2][CH2:3]1
To a solution of methyl 4-cyclopropyl-2-methylbenzoate (compound 142.1, 2.68 g, 13.4 mmol, 1.00 equiv, 95%) in AcOH (50 mL) were added NaIO4 (1.51 g, 7.08 mmol, 0.50 equiv), I2 (3.58 g, 14.1 mmol, 1.00 equiv), and sulfuric acid (201 mg, 2.01 mmol, 0.15 equiv, 98%). The reaction mixture was stirred at 110° C. overnight. After cooling to ambient temperature, 100 mL of water was added. The resulting mixture was diluted with 100 mL of ethyl acetate, then washed with 3×30 mL of Na2S2O3 (aq., sat.) and 1×30 mL of brine. The organic phase was dried over anhydrous sodium sulfate and concentrated in vacuo. The residue was purified via silica gel column chromatography with ethyl acetate/petroleum ether (1/50) as eluent to yield 2.00 g (45%) of methyl 4-cyclopropyl-5-iodo-2-methylbenzoate as a colorless oil.
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