Cesium carbonate → (S)-4-[3-(tert-Butyldimethylsilanyloxy)-2-methylpropyl]-6-fluoro-4H-benzo[1,4]oxazin-3-one

Participants

Reaction Steps

6-Fluoro-4H-benzo[1,4]oxazin-3-one (95MF88) (2.54 g, 15.2 mmol), (R)-3-bromo-2-methylpropoxy-tert-butyldimethylsilane (4.07 g, 15.2 mmol) and Cs2CO3 (12.38 g, 38 mmol) were mixed according to GP7. CC (SiO2; Heptane/EtOAc 9:1) gave the title compound (111MF01) (4.09 g, 76%). 1H NMR (CDCl3) δ 6.93-6.87 (m, 1H), 6.92-6.88 (m, 1H), 6.68-6.63 (m, 1H), 4.56 (m, 2H), 4.01 (m, 1H), 3.78 (m, 1H), 3.58 (m, 1H), 3.45 (m, 1H), 2.11 (m, 1H), 0.92 (s, 12H), 0.06 (d, J=0.8 Hz, 6H); 13C NMR (CDCl3) δ 164.8, 158.5 (d, J=239.9 Hz), 141.6 (d, J=2.7 Hz), 130.1 (d, J=10.7 Hz), 117.6 (d, J=9.3 Hz), 109.6 (d, J=23.1 Hz), 103.6 (d, J=28.8 Hz), 67.8, 65.9, 44.2, 34.5, 26.0, 18.4, 14.9, −5.4, −5.4.

Provenance & Evidence