Reaction Steps
(2,3-Dimethoxyphenyl)-(3,5-dimethoxyphenyl)methanone (1.19 g, 3.94 mmol), cyanomethylphosphonic acid diethyl ester (1.24 ml, 7.87 mmol) in anhydrous THF (20 ml), and lithium bis (trimethylsilyl)amide (1.0 M solution in THF, 7.9 ml, 7.87 mmol) were treated in the same manner as described above for the synthesis of 3-(2,3-dihydrobenzo[1,4]dioxin-6-yl)-3-(3,5-dimethoxyphenyl)acrylonitrile. The crude material was purified via flash column chromatography (5% EtOAc in hexane gradient to 20% EtOAc in hexane in about 40 min.) to give 3-(2,3-Dimethoxy-phenyl)-3-(3,5-dimethoxy-phenyl)-acrylonitrile as a clear light pink oil (1.16 g, 91%): 1HNMR (DMSO-d6) δ 7.21-7.08 (m, 2H, Ar), 6.83-6.79 (m, 1H, Ar), 6.62-6.56 (m, 1H, Ar), 6.47-6.46 (m, 2H, Ar), 6.00 (s, 1H, double bond proton), 3.86-3.72 (multiple singlets, 12H, 4OCH3): 13C NMR (CDCl3) δ 161.0, 160.9, 160.7, 160.4, 153.2, 153.1, 147.3, 146.7, 140.5, 140.1, 133.9, 131.7, 124.3, 124.0, 122.5, 122.2, 117.7, 117.5, 114.1, 107.0, 105.7, 102.0, 101.9, 97.8, 97.2, 60.9, 60.7, 56.1, 56.0, 55.7, 55.6; Anal. Calcd. For C19H19NO4: C, 73.20; H, 5.80; N, 4.74. Found: C, 73.10; H, 5.72; N, 4.68.
