Triphenylphosphine → 2-acetylsulfanylmethyl-3-(6-[N,N-bis(tert-butoxycarbonyl)amino]-5-methyl-pyridin-3-yl)-2-methyl-propionic acid ethyl ester

Participants

Reaction Steps

Diisopropyl azodicarboxylate (755 μL, 3.91 mmol) was added dropwise to a solution of triphenylphosphine (1.026 g, 3.91 mmol) in THF (10 mL) at 0° C. and the reaction was stirred for 30 min. A solution of thiolacetic acid (279 μL, 3.91 mmol) and 3-(6-[N,N-bis(tert-butoxycarbonyl)amino]-5-methyl-pyridin-3-yl)-2-hydroxymethyl-2-methyl-propionic acid ethyl ester (885 mg, 1.96 mmol) in THF (5 mL) was added dropwise during 10 min. The reaction was stirred for 60 min. at 0° C. and then for 16 h at room temperature. Concentration under reduced pressure followed by chromathography (heptane/EtOAc, 10:1→1:3) gave impure 2-acetylsulfanylmethyl-3-(6-[N,N-bis(tert-butoxycarbonyl)amino]-5-methyl-pyridin-3-yl)-2-methyl-propionic acid ethyl ester (1.46 g)

Provenance & Evidence