反应详情

A solution of (R)-4-((R)-1-(tert-butoxy)ethyl)-3-(4-methoxybenzyl)oxazolidin-2-one (5.90 g, 19.2 mmol) in CH2Cl2 (40 mL) was treated with TFA (40 mL) at room temperature for 20 min. The reaction mixture was concentrated in vacuo, then diluted with CH2Cl2 (˜50 mL), and again concentrated. This procedure was repeated three times to remove TFA. Flash column chromatography (EtOAc/Heptane 30-100%) gave 3.81 g of the desired product. 1H NMR (400 MHz, MeOD) δ 7.31-7.21 (m, 2H), 7.00-6.87 (m, 2H), 4.67 (d, J=15.0 Hz, 1H), 4.34-4.18 (m, 3H), 3.95 (q, J=6.2 Hz, 1H), 3.80 (s, 3H), 3.68 (dt, J=8.7, 5.5 Hz, 1H), 1.09 (d, J=6.4 Hz, 3H). MS m/z 252.2 (M+H).

1. concentrationThe reaction mixture was concentrated in vacuo
2. additiondiluted with CH2Cl2 (˜50 mL)
3. concentrationagain concentrated
4. customto remove TFA