Tert-butyl 4-((6-chloro-3-pyridinyl)sulfonyl)-2-oxo-1-piperazinecarboxylate → Tert-butyl (2-(((6-chloro-3-pyridinyl)sulfonyl)(2-oxo-3-pentyn-1-yl)amino)ethyl)carbamate

Participants

Reaction Steps

To a slurry of tert-butyl 4-((6-chloro-3-pyridinyl)sulfonyl)-2-oxo-1-piperazinecarboxylate (1.16 g, 3.09 mmol) in THF (5.0 mL) at 0° C. was added a solution of prop-1-yn-1-ylmagnesium bromide (0.5 M in THF, 13 mL, 6.50 mmol, Sigma-Aldrich, St. Louis, Mo.). After 1.5 h at 0° C., additional prop-1-yn-1-ylmagnesium bromide (4 mL, 2.0 mmol) was added. After an additional 2.5 h at 0° C., the mixture was quenched with saturated aqueous NH4Cl (25 mL). EtOAc (40 mL) was added, the layers were separated, and the aqueous layer was extracted with EtOAc (10 mL). The combined organic extracts were dried over Na2SO4, filtered, and concentrated. The residue was purified by chromatography on silica gel using (30 to 90% EtOAc in hexanes) to give tert-butyl (2-(((6-chloro-3-pyridinyl)sulfonyl)(2-oxo-3-pentyn-1-yl)amino)ethyl)carbamate as a yellow powder (1.05 g)

Provenance & Evidence