Diethyl (cyanomethyl)phosphonate → 3,3-Bis-(3,5-dimethoxy-phenyl)-acrylonitrile

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Reaktionsschritte

Bis-(3,5-dimethoxyphenyl)methanone (1.29 g, 4.27 mmol), cyanomethylphosphonic acid diethyl ester (1.34 ml, 8.53 mmol) in anhydrous THF (10 ml), and lithium bis(trimethylsilyl)amide (1.0 M solution in THF, 8.53 ml, 8.53 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 40% EtOAc in hexane in about 45 min.) to give 3,3-bis-(3,5-dimethoxy-phenyl)-acrylonitrile as an off-white solid (1.06 g, 76%): mp, 149-151° C.; 1HNMR (DMSO-d6) δ 6.66-6.62 (m, 2H, Ar), 6.50-6.47 (m, 4H, Ar), 6.39 (s, 1H, double bond proton), 3.76 (s, 6H, 2OCH3), 3.74 (s, 6H, 2OCH3); 13C NMR (CDCl3) δ 163.0, 160.9, 160.8, 140.8, 138.7, 117.7, 107.8, 106.9, 102.4, 102.2, 95.5, 55.6; Anal. Calcd. For C19H19NO4: C, 70.14; H, 5.89; N, 4.30. Found: C, 69.93; H, 5.96; N, 4.18.

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