Triethylamine → (9S,13S)-15-benzyl 13,9-di-tert-butyl 3,11-dioxo-1-phenyl-2-oxa-4,10,12-triazapentadecane-9,13,15-tricarboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of L-Glu(OBn)-OtBu hydrochloride (3.13 mg, 9.49 mmol) and triphosgene (923 mg, 3.13 mmol) in DCE (70 mL) cooled to −78° C. was added triethylamine (2.80 mL) under nitrogen. After stirring at −78° C. for 2 h, a solution of L-Lys(Z)-OtBu (3.88 g, 10.40 mmol) and TEA (1.5 mL) in DCE (10 mL) was added. The mixture was allowed to come to room temperature over a period of 1 h and stirred at room temperature overnight. The reaction was quenched with 1N HCl, and extracted with DCM. The organic layer was dried and concentrated under reduced pressure and the residue was purified utilizing a Biotage SP4 to afford (9S,13S)-15-benzyl 13,9-di-tert-butyl 3,11-dioxo-1-phenyl-2-oxa-4,10,12-triazapentadecane-9,13,15-tricarboxylate as a colorless oil (4.71 g, 76%). 1H NMR (400 MHz, CDCl3) δ 7.34-7.29 (m, 10H), 5.13-5.04 (m, 6H), 4.97 (brs, 1H), 4.38-4.28 (m, 2H), 3.18-3.14 (m, 2H), 2.50-2.35 (m, 2H), 2.19-2.10 (m, 1H), 1.94-1.85 (m, 1H), 1.79-1.72 (m, 1H), 1.58-1.33 (m, 21H).

Provenance & Evidence