(S)-Methyl 2-(((benzyloxy)carbonyl)amino)butanoate → Benzyl [(1S)-1-formylpropyl]carbamate

Temperature

-78 °C

To a solution of (S)-methyl 2-(((benzyloxy)carbonyl)amino)butanoate (2.0 g, 7.96 mmol) in toluene (50 mL) was added dropwise at −78° C. under argon DIBAL-H (1M in toluene) (15.9 mL, 15.9 mmol) over a period of 20 minutes and the reaction mixture was stirred at −78° C. for 1 hour. The reaction mixture was quenched at −78° C. with aqueous 1.5 M potassium sodium tartrate solution (20 mL), and was allowed to warm to room temperature. The reaction mixture was extracted with a solution of EtOAc and brine. The combined organic layers were dried over Na2SO4, filtered and concentrated. The residue was purified by column chromatography (24 g SiO2) using EtOAc in hexane from 0% to 30% in order to give the title compound (1.18 g, 64%) as a colorless oil. LC-MS: [M+H] 222.2; Rt 1.01 min; (LCMS method 1). 1H NMR (400 MHz, CHCl3-cf): 9.61 (s, 1H), 7.27-7.43 (m, 5H), 5.39 (br s, 1H), 5.15 (m, 2H), 4.15 (q, 1H), 1.96-2.11 (m, 1H), 1.64-1.82 (m, 1H), 1.01-0.79 (m, 3H).

1. customThe reaction mixture was quenched at −78° C. with aqueous 1.5 M potassium sodium tartrate solution (20 mL)
2. temperatureto warm to room temperature
3. extractionThe reaction mixture was extracted with a solution of EtOAc and brine
4. dry with materialThe combined organic layers were dried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated
7. customThe residue was purified by column chromatography (24 g SiO2)

ORD record

ord-e5c0a4467c2f413fb97b3ffb66f4775b

Source dataset

uspto-grants-2016_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09296733B2