Cesium carbonate → (S)-3-((S)-3-(4-(4-Bromo-3-(trifluoromethoxy)benzyloxy)-phenyl)-3-(isoxazol-3-yl)propanoyl)-4-benzyloxazolidin-2-one

Participants

Reaction Steps

A mixture of 28.3 (1.30 g, 4.80 mmol), thionyl bromide (1.01 g, 4.84 mmol), and DMF (0.1 mL) in DCM (8.0 mL) was stirred at room temperature for 50 minutes. The solvent was then removed. To the residue was added 7.5 (1.10 g, 2.80 mmol) and Cs2CO3 (1.10 g, 3.36 mmol) in DMF (8.0 mL). The mixture was stirred at room temperature for 4 hours. EtOAc (150 mL) was added, and the mixture was washed with brine (25×3 mL) and dried with MgSO4. The solvent was removed, and the crude product was purified by CombiFlash, eluting with EtOAc and hexane, to give the title compound 28.4. 1H NMR (CDCl3) δ 2.77 (dd, J=4.2, 9.5 Hz, 1 H), 3.21 (dd, J=4.2, 9.5 Hz, 1 H), 3.52 (dd, J=8.6, 17.6 Hz, 1 H), 4.04 (dd, J=8.6, 17.6 Hz, 1 H), 4.63 (m, 1 H), 4.76 (m, 1 H), 5.01 (s, 2 H), 6.14 (d, J=1.5 Hz, 1 H), 6.92 (d, J=6.9,Hz, 2 H), 7.20-7.35 (m, 9 H), 7.64 (d, J=8.3,Hz, 1H), 8.31 (d, J=1.5 Hz, 1 H). MS ESI (pos.) m/e: 647 (M+H).

Provenance & Evidence