5-Amino-4-cyano-2-fluoro-benzoic acid methyl ester synthesis

Yield:1149388-52-2 68%

Reaction Conditions:

with iron;acetic acid at 20; for 2 h;

Steps:

45.4

STEP 4: To a solution of methyl 4-cyano-2-fluoro-5-nitrobenzoate (785 mg, 3.5 mmol) in acetic acid (15 mL) was added iron powder (1.17 g, 21.0 mmol). The mixture was stirred vigorously at room temperature for 2 h. Insoluble solids were then removed by filtration through celite. Water was added to the filtrate and the aqueous mixture was extracted with ethyl acetate. The organic extract was washed with saturated aqueous sodium bicarbonate, dried over magnesium sulfate, filtered, and concentrated. The residue was purified by column chromatography (30% ethyl acetate in hexanes) to provide methyl 5-amino-4-cyano-2-fluorobenzoate (463 mg, 2.38 mmol, 68% yield). ¹H NMR (400 MHz, CDCl₃): 7.30 (d, IH), 7.19 (d, IH), 4.41 (br s, 2H), 3.94 (s, 3H); MS (EI) for C₉H₇FN₂O₂: 193 (M-H).

References:

WO2009/55077,2009,A1 Location in patent:Page/Page column 448