Diisopropylethylamine → 6-{(S)-2-[4-(2,6-difluoro-phenoxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-4-methyl-pentanoylamino}-nicotinic acid methyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution of (S)-2-[4-(2,6-difluoro-phenoxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-4-methyl-pentanoic acid (as prepared in Example 45, 200 mg, 0.62 mmol) in dichloromethane (10 mL) was treated with bromotripyrrolidinophosphonium hexafluorophosphate (345 mg, 0.74 mmol), N,N-diisopropylethylamine (240 mg, 1.85 mmol) and 6-aminonicotinic acid methyl ester (115 mg, 0.74 mmol). The reaction mixture was stirred at 25° C. for 18 h under nitrogen. The reaction mixture was diluted with dichloromethane, washed with 2N aqueous hydrochloric acid, saturated sodium bicarbonate solution, a saturated sodium chloride solution and dried over magnesium sulfate. The organic layer was concentrated, and the crude product was purified by ISCO flash chromatography (Teledyne Isco RediSep Flash Column 12 g; 0% to 100% ethyl acetate/hexanes) to afford 6-{(S)-2-[4-(2,6-difluoro-phenoxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-4-methyl-pentanoylamino}-nicotinic acid methyl ester (57 mg, 20%) as a light yellow solid: LR-ES-MS m/z calculated for C23H23F2N3O5 [M]+ 459, observed [M+H]+ 460; 1H NMR (300 MHz, DMSO-d6) δ ppm 0.92 (d, J=6.9 Hz, 3H) 0.94 (d, J=6.9 Hz, 3H) 1.39-1.74 (m, 2H) 1.73-1.92 (m, 1H) 3.86 (s, 3H) 4.32 (d, J=18.7 Hz, 1H) 4.64 (d, J=18.7 Hz, 1H) 4.95-5.05 (m, 1H) 5.06 (s, 1H) 7.25-7.53 (m, 3H) 8.17 (d, J=8.8 Hz, 1H) 8.29 (dd, J=8.8, 2.1 Hz, 1H) 8.87 (d, J=2.1 Hz, 1H) 11.34 (s, 1H).

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