Nitrogen → Cyclopentyl(2S,4E)-5-(4-bromophenyl)-2-[(tert-butoxycarbonyl)amino]pent-4-enoate

Participants

Reaction Conditions

Reaction Steps

A solution of cyclopentyl(2S)-2-[(tert-butoxycarbonyl)amino]pent-4-enoate (0.88 g, 3.11 mmol), 1-bromo-4-iodobenzene (0.966 g, 3.42 mmol), TBAI (1.262 g, 3.42 mmol) and NaHCO3 (0.783 g, 9.32 mmol) in acetonitrile (10 ml) was purged with N2 and palladium acetate (0.070 g, 0.311 mmol) was added. The reaction was then heated at 70° C. overnight. LCMS showed incomplete conversion and so the reaction was purged with nitrogen again and a further 0.05 eq (35 mg) of Pd(OAc)2, 0.25 eq (460 mg) of TBAI and 0.25 eq of NaHCO3 (65 mg) was added and stirred for another 24 hr at 70° C. After cooling to room temperature, the solvent was removed under reduced pressure. The crude residue was absorbed onto silica and purified by column chromatography eluting with 10% EtOAc in iso-hexane. Yield=715 mg, 1.631 mmol, 52.5% yield. LCMS purity>90%: m/z 438 and 440 [M+H]+.

Provenance & Evidence