反应详情

An oven-dried 1 L round-bottomed flask was charged with compound 10.5 (33.5 g, 91.3 mmol), 4-hydroxybenzotrifluoride (16.3 g, 101 mmol), triphenylphosphine (28.7 g, 109 mmol) and THF (335 mL). Next, diethyl azodicarboxylate (17.0 mL, 110 mmol) was added dropwise at 0° C., and the reaction was stirred at room temperature for 30 min. The reaction mixture was concentrated and purified by flash chromatography (SiO2 gel 60 N, eluted with 10% AcOEt/hexanes—15% AcOEt/hexane—20% AcOEt/hexane). The fractions containing only desired product were combined and concentrated to a slightly yellow oil (43.4 g). 1H NMR (400 MHz) (CDCl3) δ 7.54 (2H, d, J=8.8 Hz); 7.42 (1H, d, J=1.6 Hz); 7.34-7.30 (2H, m); 7.09 (1H, dd, J=1.8, 8.2 Hz); 6.99 (2H, d, J=8.8 Hz); 6.76-6.72 (2H, m); 5.00 (2H, s); 4.68 (2H, s); 4.28 (2H, q, J=7.1 Hz); 2.29 (3H, s); 1.31 (3H, t, J=7.2 Hz).

1. concentrationThe reaction mixture was concentrated
2. custompurified by flash chromatography (SiO2 gel 60 N, eluted with 10% AcOEt/hexanes—15% AcOEt/hexane—20% AcOEt/hexane)
3. additionThe fractions containing only desired product
4. concentrationconcentrated to a slightly yellow oil (43.4 g)