反应详情

3-Hydroxy-3-(4-nitrophenyl)-2-cyanoacrylonitrile (21.5 g, 0.10 mol) was dissolved in acetonitrile (430 mL) and of methanol (43 mL) in a flask equipped with a dropping funnel, a thermometer, a stir bar, and argon atmosphere. The flask was immersed in a −15° C. bath to the level that the internal temperature was maintained between −5° C. and 0° C. (75 mL of a 2.0 M solution in diethyl ether, 0.15 mol) was added dropwise over 20 min. HPLC analysis showed incomplete reaction, and an additional portion (25 mL, 0.05 mol) of trimethylsilyldiazomethane solution was added. This was repeated with 35 mL (0.07 mol). After 20 min, the mixture was poured into a rapidly-stirred solution of acetic acid (15 g, 0.25 mol) in EtOAc (1.8 L). The mixture was extracted with water (3×1.5 L), filtered through phase separation paper, and concentrated in vacuo. the solid residue weighed 14.4 g and was used in the next step without further purification. NMR (60 MHz) (CDCl3) δ 8.0 (AB, 4H); 4.0 (s, 3H).

1. customequipped with a dropping funnel
2. customwas immersed in a −15° C.
3. additionwas added dropwise over 20 min
4. customreaction
5. extractionThe mixture was extracted with water (3×1.5 L)
6. filtrationfiltered through phase separation paper
7. concentrationconcentrated in vacuo
8. customwas used in the next step without further purification