反应详情

To a solution of (2R,4S)-ethyl 5-(biphenyl-4-yl)-4-(2-methoxyoxazole-5-carboxamido)-2-methylpentanoate, intermediate 20, (175 mg, 0.40 mmol) in dioxane (5 mL) is added a solution of 4M HCl in dioxane (501 μL, 2.01 mmol) at room temperature. After stirring at room temperature for 1 hour, the reaction mixture is concentrated under reduced pressure. The obtained residue is purified by RP-HPLC (SunFire C18, H2O(0.1% TFA)/CH3CN), and then lyophilized to give (2R,4S)-ethyl 5-(biphenyl-4-yl)-2-methyl-4-(2-oxo-2,3-dihydrooxazole-5-carboxamido)pentanoate (154 mg). HPLC retention time=1.89 minutes (condition B); MS 423.3 (M+1). 1HNMR (400 MHz, DMSO-d6) δ ppm 1.07 (d, J=7.1 Hz, 3H) 1.11 (t, J=7.1 Hz, 3H) 1.61 (ddd, J=14.0, 10.2, 4.3 Hz, 1H) 1.81 (ddd, J=13.8, 9.9, 3.9 Hz, 1H) 2.41-2.50 (m, 1H) 2.73 (dd, J=13.3, 7.3 Hz, 1H) 2.83 (dd, J=13.3, 7.3 Hz, 1H) 3.99 (q, J=7.1, 2H) 4.05-4.22 (m, 1 H) 7.26 (d, J=8.1 Hz, 2H) 7.30-7.39 (m, 1H) 7.44 (t, J=7.7 Hz, 2H) 7.53 (s, 1H) 7.58 (d, J=8.3 Hz, 2H) 7.64 (d, J=7.1 Hz, 2H) 8.10 (d, J=8.8 Hz, 1H) 11.25 (s, 1H)

1. concentrationthe reaction mixture is concentrated under reduced pressure
2. customThe obtained residue is purified by RP-HPLC (SunFire C18, H2O(0.1% TFA)/CH3CN)