Water → 4'-[2-Propoxy-5-(hydroxyiminomethyl)-4-vinylimidazol-1-ylmethyl]-3'-fluorobiphenyl-2-carboxylic acid t-butyl ester

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Reaction Conditions

Reaction Steps

Intermediate (18b) (7.2 g, 15.5 mmol) was dissolved in pyridine (30 mL). Hydroxylamine hydrochloride (4.0 g, 57.9 mmol) was added followed by water (20 mL) and the mixture was stirred at 40° C. for 2 hours. The reaction was quenched with water, extracted with 200 mL EtOAc, washed with 3×100 mL 1M phosphoric acid, 1×100 mL saturated sodium bicarbonate solution, and 2×100 mL saturated aqueous NaCl, then dried over MgSO4, filtered and concentrated in vacuo. The crude product was purified by silica gel chromatography (0-80% EtOAc:hexanes) to yield intermediate (18c) as a white solid (7.4 g). Anal. HPLC retention time=4.9 minutes. Gradient conditions: 25% solvent B/75% solvent A to 95% solvent B/5% solvent A over 6 minutes. MS m/z: [M+H+] calcd for C27H30FN3O4, 480.23. found 480.4. 1H-NMR (DMSO-d6) 10.99 (1H, s), 8.21 (1H, s), 7.67 (1H, d), 7.54 (1H, m), 7.44 (1H, s), 7.34 (1H, m), 7.11 (2H, m), 6.81 (2H, m), 5.73 (1H, d), 5.36 (2H, s), 5.10 (1H, d), 1.66 (2H, m), 1.13 (9H, s), 0.85 (4H, m).

Provenance & Evidence