Thionyl Chloride → 7-Fluorobenzofuran

To a solution of 7-fluoro-2,3-dihydrobenzofuran-3-ol (4.6 g, 29 8 mmol) in pyridine (93 mL) at 0° C. was added SOCl2 (21.7 mL, 298 mmol) dropwise. Upon completion of addition, the mixture was stirred at 0° C. for 1.5 h. At the conclusion of this period, the reaction mixture was carefully quenched with aqueous NaHCO3 (saturated, 100 mL) to reach a pH=9. Once at the prescribed pH, the reaction mixture was extracted with CH2Cl2 (4×15 mL). The combined organic layers were washed with aqueous NaHCO3 (5%, 40 mL), water (40 mL), and then concentrated to yield the crude product. The crude product was dissolved in CH2Cl2 (50 mL), washed with aqueous HCl (1 N, 5×10 mL), and then water (40 mL). The organic layer was separated, dried (MgSO4), filtered, and concentrated to afford Compound 1C as a brown oil (2.56 g). 1H NMR (500 MHz, CDCl3) δ ppm 7.67 (d, J=2.2 Hz, 1 H), 7.33-7.40 (m, 1 H), 7.17 (td, J=8.0, 4.4 Hz, 1 H), 7.04 (dd, J=10.7, 8.0 Hz, 1 H), 6.79-6.85 (m, 1 H).