2-Fluoro-4-nitrophenol → Methyl 7-(2-fluoro-4-nitrophenoxy)thieno[3,2-b]pyridine-2-carboxylate

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Reaction Conditions

Reaction Steps

A mixture of 37 (4.0 g, 17.6 mmol), 2-fluoro-4-nitrophenol (5.5 g, 35.0 mmol) and K2CO3 (12.1 g, 87.5 mmol) in Ph2O was heated at 180° C. for 5 hours. The mixture was cooled to room temperature, diluted with EtOAc and washed with water. The organic phase was collected, dried over anhydrous sodium sulfate and the solvents were removed under reduced pressure. The residue was purified by flash chromatography using hexane—AcOEt (70:30) as an eluent. The product from the column was re-crystallized from a mixture of ethyl acetate-hexanes to afford 38 (3.6 g, 59% yield) as a white solid. 1H NMR (400 MHz, DMSO-d6) δ(ppm): 8.69 (d, J=5.2 Hz, 1H), 8.47 (dd, J=2.4 and 10.0 Hz, 1H), 8.27 (s, 1H), 8.21 (m, 1H), 7.77 (dd, J=8.0 and 9.2 Hz, 1H), 7.06 (dd, J=0.8 and 5.2 Hz, 1H), 3.93 (s, 3H).

Provenance & Evidence