[CH2:1]([C:3]1[CH:8]=[C:7]([F:9])[CH:6]=[CH:5][C:4]=1[OH:10])[CH3:2].C(N(CC)CC)C.Cl[C:19]([O:21][CH3:22])=[O:20]>CN(C1C=CN=CC=1)C.ClCCl>[C:19](=[O:20])([O:21][CH3:22])[O:10][C:4]1[CH:5]=[CH:6][C:7]([F:9])=[CH:8][C:3]=1[CH2:1][CH3:2]2-Ethyl-4-fluorophenol (2 g, 14.27 mmol) and DMAP (87 mg, 0.71 mmol) was dissolved in dichloromethane (10 mL) and triethylamine (4 mL, 28.5 mmol), cooled to 0° C., then treated with methyl chloroformate (2.02 g, 1.65 mL, 21.40 mmol) and allowed to warm to room temperature over 2 h. The reaction was quenched with water, the layers separated, and the aqueous layer was extracted with dichloromethane. The combined organic extracts were dried over Na2SO4, filtered and concentrated. Purification by silica gel chromatography (20% ethyl acetate/hexane) provided 2-ethyl-4-fluorophenyl methyl carbonate (2.4 g, 85% yield). 1H NMR (400.0 MHz, DMSO-d6) δ 7.26-7.17 (m, 2H), 7.12-7.07 (m, 1H), 5.76 (s, 1H), 3.83 (d, J=4.3 Hz, 2H), 2.54-2.48 (m, 2H), 1.12 (t, J=7.6 Hz, 3H).
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