Water → 2,4-Dimethoxy-5-thien-2-ylbenzaldehyde

Participants

Reaction Steps

Ex-1A: A solution of 5-bromo-2,4-dimethoxy-benzaldehyde (10.0 g, 40.80 mmol) and thiophene-2-boronic acid (7.8 g, 60.96 mmol) in ethylene glycol dimethyl ether (250 mL) was stirred at room temperature under nitrogen for 15 min. Tetrakis(triphenylphosphine)-palladium(0) (4.85 g, 4.19 mmol) and a sodium carbonate solution (2 M, 70 mL) were then added, and the resulting mixture was refluxed under nitrogen overnight. Upon codling to room temperature the reaction was poured into water (250 mL) and extracted with dichloromethane (2×250 mL). The organic phase was dried over sodium sulfate, filtered, and the solvent was removed under reduced pressure. Silica gel chromatography (hexane/ethyl acetate, 3:1) gave 9.2 g (91%) of the desired 2,4-dimethoxy-5-thiophen-2-yl-benzaldehyde product as a pale yellow solid, m.p. 125–126° C. 1H-NMR (300 MHz, CDCl3) δ 10.34 (s, 1H), 8.12 (s, 1H), 7.44 (dd, 1H, J=3.5 and 1.5 Hz), 7.31 (dd, 1H, J=5.2 and 1.5 Hz), 7.07 (dd, 1H, J=5.2 and 3.5 Hz), 6.51 (s, 1H), 4.02 (s, 3H), 3.99 (s, 3H)

Provenance & Evidence