Dimethylformamide → Fmoc-glycylglycine-4,4'-dimethoxytrityloxybutylamide

Participants

Reaction Steps

To a solution (70 ml) of Fmoc-glycylglycine (Fmoc-GlyGly-OH, purchased from China Langchem) (2.50 g, 7.05 mmol), dicyclohexylcarbodiimide (1.75 g, 8.46 mmol) and 1-hydroxybenzotriazole monohydrate (2.59 g, 16.92 mmol) in anhydrous N,N-dimethylformamide was added a solution (50 ml) of compound 12 (3.31 g, 8.46 mmol) in anhydrous N,N-dimethylformamide under ice-cooling under an argon atmosphere. After removing the ice bath, the mixture was stirred at room temperature overnight under an argon atmosphere. The resulting precipitate was filtered off, and the filtrate was concentrated at 35° C. under reduced pressure. To the obtained residue was added dichloromethane (200 ml), and the mixture was washed twice with saturated brine. The organic layer was fractionated, dried over sodium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: dichloromethane-methanol (95:5)+0.05% pyridine, and then dichloromethane-methanol (9:1)+0.05% pyridine) to give Fmoc-glycylglycine-4,4′-dimethoxytrityloxybutylamide (13) (3.49 g, 68%) as a colorless syrup.

Provenance & Evidence