Reaction Steps
(3,5-dimethoxyphenyl)-(3-methoxyphenyl)methanone (0.31 g, 1.12 mmol), malononitrile (0.08 ml, 1.23 mmol), and aluminum oxide (0.57 g, 5.6 mmol) were mixed and heated in an oil bath at 160° C. overnight. After cooling down to r.t., the brown mixture was extracted with CH2Cl2 (50 ml), filtered through a Celite pad and concentrated to an oil, which was purified via flash column chromatography (5% EtOAc in hexane gradient to 20% EtOAc in hexane in about 40 min.) and lyophilized to give 2-[(3,5-dimethoxy-phenyl)-(3-methoxy-phenyl)-methylene]-malononitrile as a greenish solid (0.12 g, 34%): mp, 100-102° C.; 1HNMR (DMSO-d6) δ 7.47 (t, J=8 Hz, 1H, Ar), 7.22 (dd, J=2.36, 8 Hz, 1H, Ar), 7.16 (t, J=1 Hz, 1H, Ar), 6.96 (d, J=7 Hz, 1H, Ar), 6.78 (t, J=2 Hz, 1H, Ar), 6.62 (d, J=2 Hz, 2H, Ar), 3.79 (s, 3H, OCH3), 3.76 (s, 6H, 2OCH3); 13C NMR (DMSO-d6) δ 173.4, 160.3, 158.9, 137.5, 136.8, 130.1, 122.4, 118.0, 115.3, 114.1, 114.0, 108.1, 103.6, 82.9, 55.6, 55.5; Anal. Calcd. For C19H16N2O3: C, 71.24; H, 5.03; N, 8.74. Found: C, 71.10; H, 4.87; N, 8.59.
