4-Methoxybenzaldehyde → Cinnamoylbenzene

Participants

Reaction Steps

To a solution of 1-(6-hydroxy-2,3,4,-Trimethoxyphenyl)ethanone 5 (2.26 g, 10 mmol), 4-methoxybenzaldehyde (1.63 g, 12 mmol) and t-BuOK (2.11 g, 22 mmol) in ethanol (30 mL) was refluxed for 4 h. The reaction mixture was poured onto crushed ice (100 g). The resulting precipitate was filtered and washed with water. The residue was air-dried at room temperature. The crude product was recrystallized from ethyl acetate to afford chalcone as orange crystals (2.99 g, 87%): 1H NMR (CDCl3, 200 M Hz) δ 11.75 (br s, 1H), 7.84 (s, 2H), 7.60 (d, J=8.8 Hz, 2H), 6.93 (d, J=8.8 Hz, 2H), 6.29 (s 1H), 3.93 (s 3H), 3.90 (s, 3 M), 3.85 (s, 3H), 3.84 (s, 3H); 13C NMR (CDCl3, 50 M Hz) δ 192.7 (s), 162.6 (s), 161.5 (s), 159.9 (s), 154.9 (s), 143.3 (d), 135.2 (s), 130.1 (d, 2C), 128.0 (s), 124.0 (d), 114.4 (d, 2C), 108.7 (s), 96.5 (d), 61.8 (q), 61.2 (q), 56.0 (q), 55.3 (q).

Provenance & Evidence