p-Toluenesulfonic acid → Ac-Gly-Sar-OBzl

Participants

Reaction Steps

Ac-Gly-OH a (4.10 g, 35.0 mmol), Sar-OBzl.PTSA b (11.71 g, 33.3 mmol), triethylamine (5.58 mL, 40.0 mmol), HOBt (1.35 g, 10 mmol) and DCC (8.25 g, 40.0 mmol) were stirred in 200 mL THF overnight. The mixture was filtered to discard DCU and removed THF in vacuum. The concentrated residue was dissolved in 100 mL ethyl acetate and washed with 100 mL 10% citric acid(aq) twice, 100 mL 5% NaHCO3(aq) twice and 100 mL brine twice, dried over MgSO4, and evaporated in vacuum to get about 9 g light yellow oily Ac-Gly-Sar-OBzl c.

Provenance & Evidence