[CH2:1]([O:3][C:4]1[CH:5]=[C:6]([CH:9]=[CH:10][C:11]=1[O:12][CH3:13])[CH:7]=O)[CH3:2].C([O-])([O-])=O.[K+].[K+].P(=O)([O-])O[C:22](CC)(CC)[C:23]#[N:24]>C(O)C>[CH2:1]([O:3][C:4]1[CH:5]=[C:6](/[CH:7]=[CH:22]/[C:23]#[N:24])[CH:9]=[CH:10][C:11]=1[O:12][CH3:13])[CH3:2]3-Ethoxy-4-methoxybenzaldehyde (4.5 g, 25 mmol), K2CO3 (5.2 g, 37.5 mmol), and diethylcyanomethyl phosphonate (4.2 mL, 26.3 mmol) were combined in ethanol (75 mL). The mixture was stirred at reflux for 1.5 h. After all benzaldehyde had been consumed, the reaction mixture was concentrated to about 15 mL, and diluted with CH2Cl2 (150 mL) and H2O (150 mL). The mixture was shaken in a separatory funnel and the layers separated. The organic layer was dried with Na2SO4, filtered and concentrated. The crude product was then titurated from ether to afford >99% of the (E)-3-(3-ethoxy-4-methoxyphenyl)-acrylonitrile 3.03 g as a light tan powder, 60%: 1H NMR (400 M Hz, CDCl3) δ 7.32 (d, 1H, J=16.4 Hz), 7.03 (dd, 1H, J=8.4, 2.0 Hz), 6.94 (d, 1H, J=2.0 Hz), 6.87 (d, 1H, J=8.4 Hz), 6.51 (d, 1H, J=16.8 Hz), 4.11 (q, 2H, J=6.8 Hz), 3.91 (s, 3H), 1.49 (t, 3H, J=6.8 Hz).
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