Step 2: Synthesis of intermediate 2
A mixture of Intermediate 1 (methyl 3-(bromomethyl)-4-chlorobenzoate, 1.00 g, 3.80 mmol), trimethylcyanosilane (TMSCN, 0.56 g, 5.69 mmol), and potassium carbonate (K2CO3, 786 mg, 5.69 mmol) in acetonitrile (CH3CN, 50 mL) was heated to reflux for 16 hours. After completion of the reaction, the mixture was cooled to room temperature, filtered to remove insoluble material and the filtrate was concentrated. The resulting crude product was purified by silica gel column chromatography using a hexane solution of 5-10% ethyl acetate (EtOAc) as eluent to afford the target product methyl 3-cyanomethyl-4-chlorobenzoate (590 mg, 75% yield) as a white solid.
1H NMR (400 MHz, CDCl3) δ: 8.18 (d, 1H), 7.99 (dd, 1H), 7.52 (d, 1H), 3.94 (s, 3H), 3.88 (s, 2H).
