HCID 59468979, compound → HCID 59468978, compound

Participants

Reaction Steps

To a solution of 1-(1,1-dimethylethyl) 2-methyl (2S,5S)-2-(cyanomethyl)-5-{4-[(phenylmethyl)oxy]phenyl}-1,2-pyrrolidinedicarboxylate (D77, 500 mg, 1.11 mmol) in methanol (30 ml) was added Raney Nickel (slurry in water, 1 spatula) and the mixture was stirred under a hydrogen atmosphere (6 atm) for 6 hours. The catalyst was filtered off, the solvent removed under reduced pressure, and the solid residue was treated two times with toluene and dried under vacuum. The dry white solid obtained was refluxed in methanol (30 ml) for six hours until cyclization was complete. The solvent was removed under reduced pressure and the crude material purified by chromatography on silica gel using dichloromethane/methanol (1:0 to 92:8) to afford the title compound as a white solid (130 mg, 35%); Rt (HPLC): 3.89 min; Rf (dichloromethane/methanol=9:1): 0.41; MS: (ES/+) m/z: 665 [2M+Na+], 355 [M+Na+]; C18H24N2O4 requires 332; 1H NMR (400 MHz, DMSO-d6) δ(ppm): 9.11 (s, 1H); 7.76 and 7.66 (s, s, 1H); 7.43 (dd, 2H); 6.66 (dd, 2H); 4.81-4.70 (m, 1H); 3.29-3.20 (m, 1H); 3.19-3.09 (m, 1H); 2.47-2.20 (m, 2H); 2.08-1.85 (m, 2H); 1.84-1.74 (m, 1H); 1.68-1.52 (m, 1H); 1.33 and 1.08 (s, s, 9H).

Provenance & Evidence