Dicyclohexylcarbodiimide → Carboxy methyl-t-butyl disulfide glycyl glycine t-butyl ester

Participants

Reaction Steps

A solution of 23.85 g (115.6 mmol) DCC in 430 ml CH2Cl2 was dropwise added to a solution of 21.76 g (115.6 mmol) Gly-Gly-O-tBu, 20.84 g (115.6 mmol) Carboxy methyl-t-butyl disulfide and 13.3 g (115.6 mmol) NHS in 1 l CH2Cl2. The resulting suspension was stirred over night under N2-atmosphere at room temperature. After filtration the resulting solution was washed 3× with 400 ml half-saturated aqueous NaHCO3 and 1× with 400 ml water. The dried organic layer (MgSO4) was evaporated under reduced pressure. The crude product was purified by chromatography on silica gel using a solvent gradient ranging from CH2Cl2/MeOH 99:1 to CH2Cl2/MeOH 98.5:1.5. 26.1 g (64%) were isolated as a yellow oil.

Provenance & Evidence