Acetic Acid → HCID 59556868, compound

Temperature

-78 °C

A solution of diisopropylamine (0.665 mL) in THF (25 mL) was cooled to −78° C., and n-butyllithium-hexane solution (2.93 mL, 1.6 mol/L) was added dropwise. After the completion of the dropwise addition, the mixture was stirred at −78° C. for 1 hr. Subsequently, ethyl 2-methylpropanoate (0.675 mL) was added dropwise, and the mixture was further stirred at −78° C. for 1 hr. A solution of benzyl (4S)-4-methyl-2,5-dioxo-1,3-oxazolidine-3-carboxylate (900 mg) in THF (5.0 mL) was added dropwise at −78° C., and the mixture was further stirred at −78° C. for 20 min. Acetic acid (2.0 mL) was added to the reaction mixture and, after warming to room temperature, water was added, and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: hexane/ethyl acetate=1/0→1/1) to give the title compound as a colorless oil (yield: 905 mg, yield: 78.0%).

1. additionn-butyllithium-hexane solution (2.93 mL, 1.6 mol/L) was added dropwise
2. additionAfter the completion of the dropwise addition
3. stirringthe mixture was further stirred at −78° C. for 1 hr
4. stirringthe mixture was further stirred at −78° C. for 20 min
5. temperatureafter warming to room temperature
6. extractionthe mixture was extracted with ethyl acetate
7. washThe extract was washed with saturated brine
8. dry with materialdried over anhydrous magnesium sulfate
9. concentrationconcentrated under reduced pressure
10. customThe residue was purified by silica gel column chromatography (eluent: hexane/ethyl acetate=1/0→1/1)

ORD record

ord-37834fa0b7904f63b3c99802573671a8

Source dataset

uspto-grants-2013_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08420694B2