Benzyl chloroformate → HCID 57219190, compound

Participants

Reaction Steps

A solution of benzyl chloroformate (485 μL, 3.4 mmols) in methylene chloride (2.5 mL) was added dropwise to a stirred, cooled (ice/H2O bath) solution of (±)-t-butyl 2-[cis-3-amino-4-(2-(2-furyl)ethyl)-2-oxoazetidin-1-yl]acetate (1.0 g, 3.4 mmols) and diisopropylethylamine (592 μL, 3.4 mmols) in methylene chloride (10 mL). Stirring was continued with cooling for 0.5 hr and then for 0.33 hr at ambient temperatures. The solution was sequentially washed with 0.05M (pH 4) ammonium phosphate, H2O, dilute aqueous NaHCO3, and saturated NaCl. The solution was dried (Na2SO4) and concentrated, and the residue was chromatographed on SiO2 (50 g) with hexane-ethyl acetate (2:1). The appropriate fractions were combined and concentrated to leave a viscous oil which was crystallized from diethyl ether-hexane to afford the title compound (1.05 g, 72% yield).

Provenance & Evidence