Di-tert-butyl[4-(1,3-dioxolan-2-yl)-3-fluorophenyl]malonate (2.45 g, 6.41 mmol), iodomethane (0.80 mL, 12.85 mmol) and potassium carbonate (1.78 g, 12.9 mmol) were suspended in DMF (10 mL) and heated at 70° C. for 3 hours in a sealed tube. A further portion of iodomethane was added (0.60 mL, 9.64 mmol) and heating continued at 75° C. for 3 hours. Room temperature was attained, H2O (150 mL) was added and the products extracted into Et2O (2×100 mL). The combined organic extracts were washed with brine, dried over MgSO4 and concentrated in vacuo. Purification of the residue by MPLC gave the clean product (orange oil). 1H NMR (CDCl3) δ 7.47 (t, J=8.1 Hz, 1H), 7.19 (dd, J=8.1, 1.8 Hz, 1H), 7.17 (dd, J=12.0, 1.8 Hz, 1H), 6.07 (s, 1H), 4.13 (m, 2H), 4.03 (m, 2H), 1.74 (s, 3H), 1.45 (s, 18H).
