Sodium Hydroxide → (2R,4S)-5-(3'-chlorobiphenyl-4-yl)-2-methyl-4-(5-oxo-4,5-dihydro-1,3,4-oxadiazole-2-carboxamido)pentanoic acid

Participants

Reaction Steps

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).

Provenance & Evidence