Hydrochloric Acid → HCID 89668615, compound

Participants

Reaction Conditions

Reaction Steps

4-Azidobenzyl (4-nitrophenyl) carbonate synthesized by the method described in the literature (Bioconjugate Chem. 2008, 19, 714) (Compound tk32) (3.46 g, 11.0 mmol) was added to a suspension of Fmoc-lysine hydrochloride (Compound tk31) (4.9 g, 12.10 mmol) and sodium bicarbonate (2.77 g, 33.0 mmol) in DMF (22 mL) under ice-cooling. The reaction mixture was stirred at 25° C. for 8 hours and 1 N hydrochloric acid was then added, followed by extraction with ethyl acetate. The organic phase was washed with brine three times and dried over sodium sulfate. Following concentration under reduced pressure, the resulting residue was purified by reverse-phase silica gel column chromatography (0.1% aqueous formic acid solution/0.1% formic acid-acetonitrile solution) to afford (S)-2-((((9H-fluoren-9-yl)methoxy)carbonyl)amino)-6-((((4-azidobenzyl)oxy)carbonyl)amino)hexanoic acid (Compound SP661) (5.5 g, 92%).

Provenance & Evidence