ethyl 3-(4-fluorophenyl)-2-oxopropanoate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of ethyl 3-(4-fluorophenyl)-2-oxopropanoate (4 g, 19.03 mmol, 1.00 equiv) and triethoxymethane (16 mL) in acetic anhydride (5 mL) was stirred at 130° C. overnight. The reaction mixture was cooled to room temperature and then concentrated under vacuum. The residue was purified on a silica gel column eluted with 0-10% of ethyl acetate in petroleum ether to give 700 mg (14%) of (E)-ethyl 4-ethoxy-3-(4-fluorophenyl)-2-oxobut-3-enoate as a yellow oil. 1H-NMR (300 MHz, DMSO-d6): δ 7.71 (s, 1H), 7.32-7.28 (m, 2H), 7.09-7.05 (m, 2H), 4.23 (q, J=7.0 Hz, 2H), 4.16 (q, J=8.0 Hz, 2H), 1.37-1.20 (m, 6H) ppm. concentrated under vacuum The residue was purified on a silica gel column eluted with 0-10% of ethyl acetate in petroleum ether

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred mixture of ethyl 2-chloro-2-oxoacetate (35 g, 256.35 mmol, 1.00 equiv) and Pd(PPh3)2Cl2 (9 g, 12.82 mmol, 0.05 equiv) in tetrahydrofuran (200 mL) maintained under nitrogen at 0° C. was added dropwise a solution of (4-fluorobenzyl)zinc(II) bromide (65 g, 255.47 mmol, 1.00 equiv) in tetrahydrofuran (500 mL). The reaction mixture was refluxed for 12 h then cooled to 0° C. and quenched by dropwise addition of 500 mL of saturated NH4Cl solution. The resulting mixture was extracted with 2×500 mL of ethyl acetate. The combined organic layers was washed with 1×1 L of brine, dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was purified on a silica gel column eluted with 0-5% of ethyl acetate in petroleum ether to give 18 g (34%) of ethyl 3-(4-fluorophenyl)-2-oxopropanoate as a yellow oil. 1H-NMR (300 MHz, DMSO): δ 7.36-7.33 (m, 2H), 7.18-7.12 (m, 2H), 4.50 (s, 1H), 4.26 (q, J=7.0 Hz, 2H), 1.20 (t, J=7.2 Hz, 3H) ppm. The reaction mixture was refluxed for 12 h then cooled to 0° C. quenched by dropwise addition of 500 mL of saturated NH4Cl solution The resulting mixture was extracted with 2×500 mL of ethyl acetate The combined organic layers was washed with 1×1 L of brine dried over anhydrous sodium sulfate concentrated under vacuum The residue was purified on a silica gel column eluted with 0-5% of ethyl acetate in petroleum ether