Water → HCID 86642472, compound

Participants

Reaction Steps

To a solution of (2S)-2-{[(benzyloxy)carbonyl]amino}-3-{[(2S)-2-{[(benzyloxy)carbonyl]amino}-2-carboxyethyl]disulfanyl}propanoic acid LXVI (5.6 g; 11 mmol) and anhydrous potassium carbonate (6.08 g; 44.0 mmol) in DMF (50 mL) cooled to 0° C. was added benzyl bromide (7.8 mL; 66.0 mmol). The mixture was stirred overnight at r.t. Water (150 mL) was added, and solution was extracted once with DCM (40 mL). The solvent was evaporated under reduced pressure and the residue was dissolved in diethyl ether (60 mL). The ether was washed with 10% aq Na2S2O3 until all the DMF was removed and once with water. The organic phase was dried over anhydrous MgSO4, evaporated and the residue purified on a silica gel column (100% CHCl3→200:3 CHCl3:MeOH). Benzyl (2S)-3-{[(2S)-3-(benzyloxy)-2-{[(benzyloxy)carbonyl]amino}-3-oxopropyl]disulfanyl}-2-{[(benzyloxy)carbonyl]amino}propanoate LXVII was obtained as a light-green viscous oil (5.9 g; 8.56 mmol; 77.8% yield). 1H NMR (CDCl3) 3.04-3.18 (m, 4H), 4.62-4.76 (m, 2H), 5.12 (s, 2H), 5.17 (s, 2H), 5.62-5.76 (m, 2H), 7.28-7.40 (m, 20H); ESIMS found for C36H36N2O8S2 m/z 689.5 (M+H).

Provenance & Evidence