Ethyl Acetate → HCID 59830897, compound

Participants

Reaction Conditions

Reaction Steps

Intermediate (18a) (10.0 g, 19.3 mmol) was dissolved in DMF (100 mL). Tetrakis(triphenylphosphine)palladium(0) (400 mg, 0.4 mmol) was added, followed by (2-ethenyl)tri-n-butyltin (8.5 mL, 29.0 mmol). The reaction vessel was fitted with a reflux condenser and was heated to 110° C. with stirring for 1 hour, under nitrogen. The mixture was cooled and 200 mL EtOAc was added. The organic layer was washed with a 20% solution of potassium fluoride (2×50 mL) followed by saturated aqueous NaCl (100 mL), then dried over MgSO4, filtered and concentrated in vacuo. The resulting material was purified by silica gel chromatography (0-80% EtOAc:hexanes) to yield intermediate (18b) as a colorless oil (7.2 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 C27H29FN2O4, 465.22; found 465.6. 4′-[2-Propoxy-5-(hydroxyiminomethyl)-4-vinylimidazol-1-ylmethyl]-3′-fluorobiphenyl-2-carboxylic acid t-butyl ester (18c): 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