Reaction #1596965

Reaction equation

L-Glu(OBn)-OtBu hydrochloride

triphosgene

L-Lys(Z)-OtBu

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

Solvents

DCE

DCE

Conditions

Workup

1. 1
   workup.WAITto come to room temperature over a period of 1 h
2. 2
   workup.STIRRINGstirred at room temperature overnight
3. 3
   OtherThe reaction was quenched with 1N HCl
4. 4
   Extractionextracted with DCM
5. 5
   OtherThe organic layer was dried
6. 6
   Concentrationconcentrated under reduced pressure
7. 7
   Otherthe residue was purified

Procedure

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).

Source