Sulfuric Acid → 3-[2-Methoxy-5-(thien-2-yl)phenyl]-1-(4-hydroxy-3-methoxyphenyl)-2-propen-1-one

Participants

Reaction Steps

To a suspension of 2-methoxy-5-(thien-2-yl)benzaldehyde (0.5 g, 2.3 mmol), obtained in the same manner as described in Ex-6A, in 5 N KOH solution was added cetyltrimethyl-ammonium chloride (CTACl, 25% in water, 4 mL, 3.0 mmol) followed by the addition of 4′-hydroxy-3′-methoxyacetophenone (0.38 g, 2.3 mmol). The mixture was stirred at room temperature overnight. Then it was acidified to about pH 1 with 6 M sulfuric acid, saturated with sodium chloride, and extracted with dichloromethane. The organic phase was washed with brine, dried and evaporated. Silica gel chromatography (hexane/ethyl acetate, 3:1 then 1:1) gave 0.61 g (73%) of a foam as the desired 3-[2-methoxy-5-(thien-2-yl)phenyl]-1-(4-hydroxy-3-methoxyphenyl)-2-propen-1-one product, m.p. 142-144° C. 1H-NMR (300 MHz, CDCl3): 8.21 (d, 1H), 7.82 (s, 1H), 7.55-7.75 (m, 4H), 6.85-7.15 (m, 4H), 6.14 (s, 1H), 4.00 (s, 3H), 3.95 (s, 3H).

Provenance & Evidence