Tetrahydrofuran → HCID 57264739, Verbindung

Temperatur

-78 °C

In a separate flask a solution of (S)-4-benzyl-2-oxazolidinone (7.75 g, 43.8 mmol) in anhydrous tetrahydrofuran (75 mL) was cooled to −78° C. under a nitrogen atmosphere. A solution of n-butyllithium (2.5 M in hexanes, 17.5 mL, 43.8 mmol) was added dropwise. The reaction was stirred at −78° C. for 15 minutes. A solution of the acid chloride in anhydrous tetrahydrofuran (40 mL) was then added. The reaction mixture was stirred at −78° C. for 20 minutes then allowed to warm to room temperature over 1 h. A saturated aqueous solution of ammonium chloride (80 mL) was added. The layers were separated and the aqueous layer was extracted with ethyl acetate (50 mL). The organic layers were combined, dried over anhydrous sodium sulfate, filtered and evaporated to give a brown oil. The residue was purified by silica gel chromatography using iso-hexanes/ethyl acetate 4:1 to yield the title compound (8.88 g, 74%) as a colourless oil. 1H NMR (300 MHz, CDCl3) δ 0.08-0.15 (m, 2H), 0.42-0.52 (m, 2H), 0.73-0.89 (m, 1H), 1.55-1.67 (m, 2H), 2.73-2.85 (m, 1H), 2.97-3.18 (m, 2H), 3.27-3.37 (m, 1H), 4.14-4.26 (m, 2H), 4.65-4.75 (m, 1H), 7.19-7.40 (m, 5H). LCMS (m/z) 274.1 [M+H], Tr=2.82 min.

1. stirringThe reaction mixture was stirred at −78° C. for 20 minutes
2. temperatureto warm to room temperature over 1 h
3. customThe layers were separated
4. extractionthe aqueous layer was extracted with ethyl acetate (50 mL)
5. dry with materialdried over anhydrous sodium sulfate
6. filtrationfiltered
7. customevaporated
8. customto give a brown oil
9. customThe residue was purified by silica gel chromatography

ORD-Eintrag

ord-70baf731ff644ec393aa668c62e32d77

Quelldatensatz

uspto-grants-2015_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09145441B2