Dicyclohexylcarbodiimide → HCID 131717224, compound

Participants

Reaction Conditions

Reaction Steps

To Boc-Leu-Gly-NHOBzl (3.89 g; 9.89 mmol) obtained in Example 1 (C) was added under ice cooling 4.5N-HCl/AcOEt (30 ml), and the solution was brought back to room temperature. The reaction was carried out for 1 hour. The solvent was distilled off under reduced pressure and the residue was dissolved in THF (100 ml). The solution was cooled with a coolant at -20° C. After TEA (1.40 ml; 10.0 mmol) was added dropwise, HOBt (1.22 g; 9.03 mmol) and Boc-Hyp-OH (1.99 g; 8.60 mmol) were added and DCC (2.31 g; 11.2 mmol) dissolved in THF (10 ml) was added dropwise. The reaction was carried out for 1 hour at -10° C. and overnight in a refrigerator. Insolubles were filtered off and the solvent was then distilled off under reduced pressure. The residue was dissolved in AcOEt and the solution was washed successively with water, 1N-HCl, water, 10% Na2CO3 and water and then dried over anhydrous MgSO4. The solvent was distilled off under reduced pressure and the residue was recrystallized from AcOEt to give Boc-Hyp-Leu-Gly-NHOBzl (2.45 g; 56%) as colorless crystals. m.p. 168°-173° C., specific rotation [α]D28 -50.8 (c= 1.0, EtOH).

Provenance & Evidence