[Synthesis]
General procedure for the synthesis of 2-acetylmethylene-3-fluoro-4-benzyloxynitrobenzene from the compound (CAS: 288385-96-6): 60% sodium hydride (82 mg, 2.05 mmol) was added batchwise to a solution of N,N-dimethylacetamide (DMA, 1.5 mL) in benzyl alcohol (221 mg, 2.05 mmol) under argon protection. The reaction mixture was stirred at room temperature for 1 hour. Subsequently, a solution of 1,2-difluoro-3-(2,2-dimethoxypropyl)-4-nitrobenzene (534 mg, 2.05 mmol) in DMA (1.5 mL) was added and stirring was continued for 3 hours at room temperature. Upon completion of the reaction, the reaction was quenched with 1N hydrochloric acid (10 mL) and extracted with ethyl acetate (3 × 10 mL). The organic layers were combined, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was dissolved in tetrahydrofuran (THF, 2 mL), 6N hydrochloric acid (0.3 mL) was added, and the reaction was stirred for 1 h at room temperature. After completion of the reaction, the solvent was removed under reduced pressure. The residue was partitioned between ethyl acetate (20 mL) and water (20 mL), and the organic layer was separated, washed with saturated saline (20 mL), dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The resulting solid was ground with ether (10 mL), filtered, washed with ether (2 × 5 mL), and dried under vacuum to afford 3-acetylmethyl-1-benzyloxy-2-fluoro-4-nitrobenzene (350 mg, 56% yield).1H NMR (CDCl3, 400 MHz) δ: 2.35 (s, 3H), 4.25 (s, 2H), 5.25 (s, 2H), 7.0 (dd, J = 8.4, 2.0 Hz, 1H), 7.32-7.5 (m, 5H), 8.0 (dd, J = 8.4, 2.0 Hz, 1H). |