Sodium Hydroxide → (2S)-4-[bis(2-{[(tert-butoxy)carbonyl]amino}ethyl)carbamothioyl]-2-{[(tert-butoxy)carbonyl]amino}butanoic acid

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Reaction Steps

To the solution of the ester XV (290 mg, 0.51 mmol) in MeOH (10 mL) was added 4 M NaOH dropwise until pH=13. The mixture was stirred overnight at r.t. before evaporating the MeOH under reduced pressure. The residue was mixed with water and washed with ether. After acidifying to pH˜3 with 2 M HCl, the product was extracted with DCM, dried over MgSO4 and concentrated under vacuum to give (2S)-4-[bis(2-{[(tert-butoxy)carbonyl]amino}ethyl)carbamothioyl]-2-{[(tert-butoxy)carbonyl]amino}butanoic acid XVI (250 mg, 0.45 mmol, 88% yield). ESIMS found for C24H44N4O8S m/z 549 (M+H).

Provenance & Evidence