Sodium hydride → HCID 22049545, compound

Participants

Reaction Steps

Into a well-stirred suspension of NaH (1.1 g, 45.8 mmol) in THF (40 mL) at R.T. was added a solution of [1-(3,5-difluorophenyl)-2-hydroxy-ethyl]-carbamic acid-tert-butyl ester (5.0 g, 18.3 mmol) in THF (20 mL) via a dropping funnel at room temperature. The resulting suspension was stirred for 3 h and then quenched carefully with 10 mL of water. The biphasic mixture was extracted with 100 mL of Et2O, washed with brine, filtered and the solvent was removed in vacuo. The gummy residue thus obtained was purified by column chromatography over silica gel (Rf=0.15, 3:2 hexane-EtOAc) to obtain 4-(3,5-difluorophenyl)-oxazolidin-2-one as a white flaky solid (2.8 g, 77% yield). M.P. 81–83° C.; 1H NMR (300 MHz, CDCl3) δ 7.23–7.03 (m, 3H), 6.08 (br s, 1H), 4.94 (dd, J=6.6 Hz, J=8.7 Hz, 1H), 4.73 (t, J=8.7 Hz, 1H), 4.13 (dd, J=6.6 Hz, J=8.7 Hz, 1H). The enantiomers were separated by HPLC on a Chiralcel OD (20×250 mm) column using 80% hexane/20% isopropyl alcohol as the eluting system at 12.0 mL/min (U.V. 254 nm). The retention times for the two isomers were 16.19 min and 20.08 min respectively.

Provenance & Evidence