反应详情

A solution of 4-fluorobenzaldehyde (8.6 mL, 0.081 mol) and carboethoxymethylene triphenylphosphorane (34 g, 0.097 mol) in toluene (400 mL) was heated at reflux for 3 h. After this time the solvent was removed in vacuo and the residue triturated in petrol:Et2O (1:1). The mixture was filtered and the filtrate evaporated. The residue was chromatographed on silica gel, eluting with petrol:Et2O (3:1), to afford the ester (14.4 g, 92%) as a low-melting colourless solid. 1H NMR (major isomer) (250 MHz, CDCl3) δ1.34 (3H, t, J=7.0 Hz), 4.26 (2H, q, J=7.0 Hz), 6.36 (1H, d, J=16 Hz), 7.07 (2H, dd, JHA-HB =8.6 Hz and JHA-F =8.6 Hz), 7.51 (2H, dd, JHB-HA =8.6 Hz and JHB-F =5.3 Hz), 7.65 (1H, d, J=16 Hz).

1. temperatureat reflux for 3 h
2. customAfter this time the solvent was removed in vacuo
3. customthe residue triturated in petrol:Et2O (1:1)
4. filtrationThe mixture was filtered
5. customthe filtrate evaporated
6. customThe residue was chromatographed on silica gel
7. washeluting with petrol:Et2O (3:1)