1,1'-Carbonyldiimidazole → (S)-2-{4-[2-fluoro-3-(1-hydroxy-1-methyl-ethyl)-phenoxy]-2-oxo-2,5-dihydro-pyrrol-1-yl}-4-methyl-pentanoic acid pyrazin-2-ylamide

Participants

Reaction Steps

A solution of (S)-2-{4-[2-fluoro-3-(1-hydroxy-1-methyl-ethyl)-phenoxy]-2-oxo-2,5-dihydro-pyrrol-1-yl}-4-methyl-pentanoic acid (prepared as in Example 143, 400 mg, 1.10 mmol), 2-aminopyrazine (208 mg, 2.18 mmol) and carbonyldiimidazole (186 mg, 1.15 mmol) in N,N-dimethylformamide (2 mL) was stirred at room temperature for 12 h. At this time the mixture was transferred to an Emrys Optimizer microwave tube and microwaved at 120° C. for 5 h. The mixture was concentrated in vacuo and the residue partioned between ethyl acetate and 0.1N aqueous hydrochloric acid. The layers were separated and the organic layer was washed with water, aqueous sodium bicarbonate solution, and dried over sodium sulfate. The mixture was filtered and concentrated in vacuo. The residue was purified by ISCO flash chromatography (RediSep silica 40 g, 70% to 100% ethyl acetate/hexanes) to afford (S)-2-{4-[2-fluoro-3-(1-hydroxy-1-methyl-ethyl)-phenoxy]-2-oxo-2,5-dihydro-pyrrol-1-yl}-4-methyl-pentanoic acid pyrazin-2-ylamide (256 mg, 53%) as an off-white fluffy powder: HR-ES-MS (m/z) calculated for C23H27FN4O4 [M+H]+ 443.2089, observed 443.2088. 1H NMR (300 MHz, DMSO-d6) δ ppm 0.93 (t, J=6.8 Hz, 6H), 1.41-1.54 (m, 1H), 1.49 (s, 6H), 1.56-1.73 (m, 1H), 1.73-1.91 (m, 1H), 4.25 (d, J=18.4 Hz, 1H), 4.60 (d, J=18.4 Hz, 1H), 4.83 (s, 1H), 5.04 (dd, J=11.0, 4.4 Hz, 1H), 5.42 (br. s., 1H), 7.24 (t, J=7.7 Hz, 1H), 7.32-7.40 (td, J=7.7, 1.5 Hz, 1H), 7.56 (td, J=7.7, 1.5 Hz, 1H), 8.38 (d, J=2.4 Hz, 1H), 8.42 (s, 1H), 9.28 (s, 1H), 11.19 (s, 1H).

Provenance & Evidence