Lithium Bromide → Methyl (S)-2-benzyloxycarbonylamino-4-oxo-5-phenylpentanoate

To a suspension of copper(I) bromide-dimethyl sulfide complex (2.6 g, 12.72 mmol, 1.2 eq.) in dry THF was added a solution of lithium bromide (2.2 g, 25.44 mmol, 2.4 eq.) in dry THF. The mixture was stirred at room temperature (RT) for 20 min, and then was cooled to −78° C. A solution of benzyl magnesium chloride (13 mL, 12.72 mmol, 1.2 eq.) followed by a solution of (S)-methyl 2-(benzyloxycarbonylamino)-4-chloro-4-oxobutanoate (3.16 g, 10.6 mmol, 1 eq.) in dry THF were added. The mixture was stirred at −78° C. for 30 min and then was quenched with sat. ammonium chloride. The mixture was extracted with ethyl acetate. The organic layers were dried over magnesium sulfate and then concentrated in vacuo. The residue was purifed by flash column (1:1 ethyl acetate:hexane) to give 2 g of (S)-methyl 2-(benzyloxycarbonylamino)-4-oxo-5-phenylpentanoate.

1. temperaturewas cooled to −78° C
2. additionwere added
3. stirringThe mixture was stirred at −78° C. for 30 min
4. customwas quenched with sat. ammonium chloride
5. extractionThe mixture was extracted with ethyl acetate
6. dry with materialThe organic layers were dried over magnesium sulfate
7. concentrationconcentrated in vacuo

ORD record

ord-25967749831e47f1883d79898753aee4

Source dataset

uspto-grants-2013_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08367732B2