Propionyl chloride → (R)-(-)-4-Benzyl-3-propionyl-2-oxazolidinone

Temperature

-78 °C

To a solution of (R)-4-benzyl-oxazolidin-2-one (3.0 g, 16.9 mmol) in THF (100 mL) at −78° C. was added n-BuLi (2.5 M hexanes, 7.1 mL, 17.8 mmol) in rapid drops via syringe. The solution was stirred for 20 min at −78° C. Propionyl chloride (1.6 mL, 18.4 mmol) was added rapidly via syringe. The reaction solution was allowed to warm slowly to rt overnight then was quenched by the addition of satd. aq. NH4Cl. The mixture was concentrated, diluted with water, and extracted with DCM (3×). The combined organic layers were dried (Na2SO4) and concentrated to give the crude product, which was purified by flash chromatography (EtOAc/hexanes) to afford the title compound as a white solid (3.70 g, 94%). 1H NMR (500 MHz, CDCl3): 7.36-7.31 (m, 2H), 7.30-7.25 (m, 1H), 7.23-7.19 (m, 2H), 4.71-4.64 (m, 1H), 4.20 (dd, J=9.1, 7.5, 1H), 4.17 (dd, J=9.1, 3.1, 1H), 3.31 (dd, J=13.4, 3.3, 1H), 2.99 (dq, J=17.9, 7.4, 1H), 2.93 (dq, J=17.9, 7.3, 1H), 2.77 (dd, J=13.4, 9.6, 1H), 1.21 (t, J=7.3, 3H).

1. temperatureto warm slowly to rt overnight
2. customthen was quenched by the addition of satd
3. concentrationThe mixture was concentrated
4. additiondiluted with water
5. extractionextracted with DCM (3×)
6. dry with materialThe combined organic layers were dried (Na2SO4)
7. concentrationconcentrated
8. customto give the crude product, which
9. customwas purified by flash chromatography (EtOAc/hexanes)

ORD record

ord-53e0c5cff72d431fae9fd0b964ae0cfb

Source dataset

uspto-grants-2010_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07855292B2