4-Methylmorpholine → 3-(11-tert-Butoxycarbonylamino-undecanoylamino)-4-hydroxy-5-(2,3,5,6-tetrafluoro-phenoxy)-pentanoic acid tert-butyl ester

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Reaction Steps

Boc-11-amino-undecanoic acid (115 mg, 0.38 mmol, 1.2 equiv), EDAC (91 mg, 0.48 mmol, 1.5 equiv), and HOBt (65 mg, 0.48 mmol, 1.5 equiv) in DMF (10 mL) were added to a dry round bottom flask equipped with a magnetic stir bar. Composition 14 (115 mg, 0.32 mmol) and N-methylmorpholine (twice distilled, 0.14 mL, 0.96 mmol, 3.0 equiv) dissolved in minimal quantity of DMF were added with constant stirring. The colorless solution slowly turned yellow as the reaction proceeded. The reaction was allowed to stir for 18 h, then EtOAc (20 mL) was added and the organic layer was washed with saturated NaHCO3 (20 mL), H2O (20 mL) and brine (20 mL), dried over Na2SO4, and concentrated in vacuo. The resulting oil was purified via column chromatography (silica gel, 1:1, hexane/EtOAc) to give 15 (56 mg, 0.088 mmol, 24% yield) as a clear, thick oil. ESMS: 637.6 (M+H), 659.2 (M+Na+).

Provenance & Evidence