Ammonium Chloride → 3-(4-Amino-2,6-dichloro-phenoxy)-quinoline-8-carboxylic acid methyl ester

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Reaction Steps

To a solution of 3-(2,6-Dichloro-4-nitro-phenoxy)-quinoline-8-carboxylic acid methyl ester (98) (1.26 mmol) and NH4Cl (370 mg, 6.91 mmol) in EtOH/THF/H2O=8 mL/4 mL/2 mL was added iron powder (386 mg, 6.91 mmol). The reaction mixture was refluxed for 3.5 h. After cooling to room temperature and insoluble materials were filtered by Celite filtration. The filtrate was concentrated and sat NaHCO3 was added to the residue, which was extracted twice with AcOEt. Organic layer was washed by brine, dried over MgSO4, and concentrated. Crude residue was purified by column chromatography (hexane/AcOEt=2/1, 80 g of silica gel) to afford compound 99 (543 mg). 1H NMR (300 MHz, DMSO-d6) δ 3.91 (3H, s), 5.77 (2H, br s), 6.78 (2H, s), 7.50 (1H, d, J=3.0 Hz), 7.61 (1H, dd, J=8.1 Hz), 7.81 (1H, dd, J=1.4, 6.4 Hz), 8.08 (1H, dd, J=1.4 Hz, 6.4 Hz), 8.93 (1H, d, J=3.0 Hz).

Provenance & Evidence