Step 1. Synthesis of methyl 4-fluoro-2-methylbenzoate: 4-fluoro-2-methylbenzoic acid (50 g, 324.38 mmol) was mixed with thionyl chloride (SOCl2, 77 g, 648.76 mmol) in methanol (200 mL), and heated to reflux for 3 hours. After completion of the reaction, the reaction mixture was concentrated under reduced pressure to afford methyl 4-fluoro-2-methylbenzoate as a brown oil (52 g, 95% yield). The product was characterized by 1H-NMR (300 MHz, CDCl3): δ 7.92-7.98 (m, 1H), 6.88-6.95 (m, 2H), 3.90 (s, 3H), 2.61 (s, 3H).
