反応 #51193

反応方程式

Diethylcyanomethyl phosphonate

NaH

4-chloro-3-fluoro benzaldehyde

Water

→

title product

3-(4-Chloro-3-fluorophenyl)-2-propenenitrile

溶媒

THF

THF

反応条件

後処理

1. 1
   workup.ADDITIONwas added portionwise over ca. 10 min
2. 2
   workup.ADDITIONwas added dropwise
3. 3
   その他The whole reaction
4. 4
   抽出the mixture extracted with EtOAc (3×50 ml)
5. 5
   乾燥The combined organics were were dried (MgSO4)
6. 6
   その他evaporated to a yellow oil which
7. 7
   その他was purified by column chromatography

実験手順

Diethylcyanomethyl phosphonate (3.2 ml, 18.9 mmol) was taken up in dry THF (20 ml) at 0° C. under nitrogen, and stirred as a 60% oil dispersion of NaH (756 mg, 18.9 mmol) was added portionwise over ca. 10 min. The resulting grey suspension was then stirred at 0° C. for 1 h, before a solution of 4-chloro-3-fluoro benzaldehyde (Lancaster Synthesis) (3 g, 18.9 mmol) in 5 ml THF was added dropwise. The whole reaction was then allowed to warm to room temperature over 60 h. Water (5 ml) was added, and the mixture extracted with EtOAc (3×50 ml). The combined organics were were dried (MgSO4) and evaporated to a yellow oil which was purified by column chromatography using 5% EtOAc in pentane as eluant to provide the title product as a mixture of geometric isomers (2.4 g, 70%); 1HNMR (400 MHz, CDCl3) δ: 5.82 (d, 1H), 7.19 (d, 1H), 7.23 (d, 1H), 7.30 (d, 1H), 7.42 (app.t, 1H); LRMS TS+ 199.1 (M+NH4+).

出典