反应详情

To a solution of 2-methoxyoxazole-5-carboxylic acid, intermediate 16, (98 mg, 0.69 mmol) and (R)-ethyl 3-amino-4-(3′-chlorobiphenyl-4-yl)butanoate hydrochloride (210 mg, 0.57 mmol) in DMF (10 mL) and CH2Cl2 (4 mL) is added HATU (272 mg, 0.72 mmol) and TEA (0.50 mL, 3.58 mmol). The crude is stirred at room temperature for 2 hrs. The crude is quenched with water and diluted in EtOAc. The organic layer is washed with water 3×, brine, dried over MgSO4, filtered, and concentrated. The crude is purified via flash chromatography using 30% EtOAc/heptane to 70% EtOAc/heptane to give (R)-ethyl 4-(3′-chlorobiphenyl-4-yl)-3-(2-methoxyoxazole-5-carboxamido)butanoate (122 mg). HPLC retention time=1.89 minutes (condition A); MS (m+1)=443.2; 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.28 (t, J=7.1 Hz, 3H), 2.52-2.66 (m, 2H), 2.94 (dd, 1H), 3.08 (dd, J=13.6, 6.3 Hz, 1H), 4.12 (s, 3H), 4.14-4.23 (m, 2H), 4.60-4.71 (m, 1H), 6.81 (d, J=8.8 Hz, 1H), 7.25-7.32 (m, 3H), 7.35 (t, J=7.7 Hz, 1H), 7.42 (s, 1H), 7.43-7.47 (m, 1H), 7.48-7.54 (m, 2H), 7.55 (t, J=1.6 Hz, 1H).

1. customThe crude is quenched with water
2. additiondiluted in EtOAc
3. washThe organic layer is washed with water 3×, brine
4. dry with materialdried over MgSO4
5. filtrationfiltered
6. concentrationconcentrated
7. customThe crude is purified via flash chromatography