Iodine → 5,6,7,4'-Tetramethoxyflavone

Participants

Reaction Steps

A solution of the chalcone 6 (1.72 g, 5 mmol) and iodine (catalytic amount) in dimethyl sulfoxide (6 mL) was refluxed for 30 min, and then the reaction mixture was poured onto crushed ice (50 g). The resulting precipitate was collected and washed with 5% sodium thiosulfate solution (30 mL) and water. Recrystallization from ethanol afforded the title flavone (1.38 g, 81%) as bright yellow crystals: 1H NMR (CDCl3, 200 M Hz) δ 7.81 (d, J=9.0 Hz, 2H), 6.98 (d, J=9.0 Hz, 2H), 6.79 (s 1H), 6.57 (s, 1H), 3.99 (s 3H), 3.98 (s, 3H), 3.92 (s, 3H), 3.87 (s, 3H); 13C NMR (CDCl3, 50 M Hz) δ 177.1 (s), 162.0 (s), 161.0 (s), 157.5 (s), 154.3 (s), 152.4 (s), 140.2 (s), 127.5 (d, 2C), 123.6 (s), 114.2 (d, 2C), 122.7 (s), 106.8 (d), 96.1 (d), 62.0 (q), 61.4 (q), 56.1 (q), 55.3 (q).

Provenance & Evidence