Diisopropylcarbodiimide → N-alpha-Benzyloxycarbonyl-L-lysine

Participants

Reaction Steps

N,N-Bis CBZ-Lysine (311 mg, 0.75 mmol) was dissolved in 56 mL of anhydrous methylene chloride at room temperature. To this solution were added DIPC (0.12 mL, 0.75 mmol), DMAP (0.61 mg, 0.5 mmol) and camptothecin (0.087 g, 0.25 mmol) at 0° C. The reaction mixture was allowed to warm to room temperature and left for 16 h. The solution was washed with 0.1 N HCl, dried and evaporated under reduced pressure to yield a light yellow solid, which was recrystallized from methanol to give camptothecin-20-ester of N,N-Bis CBZ-Lys 13. Purification of 13 was satisfactory based on TLC and HPLC analysis.

Provenance & Evidence