Ammonium Chloride → 183606-83-9

Temperature

-78 °C

A solution of (S)-methyl 2-(tert-butoxycarbonylamino)-4-(methylsulfonyl)butanoate (2 g, 6.78 mmol) in tetrahydrofuran (50 mL) was cooled to −78° C., to which potassium bis(trimethylsilyl)amide (1.0 M, toluene solution, 15 ml) was added dropwise, and the mixture was stirred at −78° C. for 2 hours and at room temperature for another 2 hours. An aqueous solution of ammonium chloride (1 M) was added, and the mixture was stirred. The reaction mixture was subjected to liquid separation. The resultant organic layer was then washed with water and brine, and dried over anhydrous magnesium sulfate. The solvent was removed under reduced pressure, and the formed solid was collected by filtration to obtain the title compound. The water layer separated previously was extracted twice with ethyl acetate. The resultant organic layers were combined, washed with water and brine, and dried over anhydrous magnesium sulfate. The ethyl acetate extracts were combined, dried and then concentrated under reduced pressure to obtain the title compound. The combined product was purified by flash column chromatography (ethyl acetate:petroleum ether, 3:1) to afford the title compound (55 mg, yield 22%) as a yellow solid.

1. additionwas added dropwise
2. stirringthe mixture was stirred
3. customThe reaction mixture was subjected to liquid separation
4. washThe resultant organic layer was then washed with water and brine
5. dry with materialdried over anhydrous magnesium sulfate
6. customThe solvent was removed under reduced pressure
7. filtrationthe formed solid was collected by filtration

ORD record

ord-c242e262e7124674a9b60b0fe37d0aa5

Source dataset

uspto-grants-2016_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09434700B2