反应详情

To a solution of (2R,4S)-ethyl 5-(3′-chlorobiphenyl-4-yl)-2-methyl-4-(5-oxo-4,5-dihydro-1,3,4-oxadiazole-2-carboxamido)pentanoate (91 mg, 0.198 mmol) in MeOH (2 mL) is added aqueous 1N NaOH (4 mL, 4 mmol). After stirring at room temperature for 2 hours, the crude is quenched with 1N HCl and concentrated under reduced pressure to remove MeOH and is diluted with EtOAc, the organic layer is washed with brine, dried over Na2SO4, filtered and 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)-5-(3′-chlorobiphenyl-4-yl)-2-methyl-4-(5-oxo-4,5-dihydro-1,3,4-oxadiazole-2-carboxamido)pentanoic acid (62 mg). HPLC retention time=1.60 minutes (condition B); MS (m+1)=430.1; 1H NMR (400 MHz, DMSO-d6) δ ppm 1.01-1.12 (d, J=7.1 Hz, 3 H) 1.60 (ddd, J=13.8, 9.9, 4.3 Hz, 1 H) 1.85 (ddd, J=13.6, 9.6, 4.0 Hz, 1 H) 2.35-2.47 (m, 1 H) 2.79 (dd, J=13.7, 7.8 Hz, 1 H) 2.86 (dd, J=13.7, 7.8 Hz, 1 H) 4.11-4.28 (m, 1 H) 7.28 (d, J=8.3 Hz, 2 H) 7.35-7.43 (m, 1 H) 7.47 (t, J=7.8 Hz, 1 H) 7.57-7.65 (m, 3 H) 7.70 (t, J=1.8 Hz, 1 H) 8.84 (d, J=8.8 Hz, 1 H) 12.05 (br. s., 1 H) 12.92 (s, 1 H).

1. customthe crude is quenched with 1N HCl
2. concentrationconcentrated under reduced pressure
3. customto remove MeOH
4. additionis diluted with EtOAc
5. washthe organic layer is washed with brine
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure
9. customThe obtained residue is purified by RP-HPLC (SunFire C18, H2O(0.1% TFA)/CH3CN)