Potassium Carbonate → (E)-3-[5-(4-methylphenyl)-thiophen-2-yl]acrylic acid

Participants

Reaction Steps

Under argon atmosphere, a solution of methyl (E)-3-(5-bromothiophen-2-yl)acrylate (4.0 g), 4-methylphenyl borate (2.64 g) and potassium carbonate (4.48 g) in toluene-ethanol-water (160-16-16 ml) was stirred at room temperature for 1 hour. To the reaction mixture was added tetrakistriphenylphosphinepalladium (0.56 g), and the mixture was refluxed for 16 hours and cooled to room temperature. The organic layer was washed with saturated sodium chloride solution, dried with magnesium sulfate and concentrated under reduced pressure to give crude product (5.24 g). To a solution of the resulting carboxylic acid ester (5.24 g) in tetrahydrofuran (100 ml) was added lN sodium hydroxide (20 ml) at room temperature, and the mixture was stirred for 5 days. To the reaction mixture was added water, and the mixture was washed with ethyl acetate. The aqueous layer was acidified with concentrated hydrochloric acid, and the mixture was extracted with ethyl acetate, washed with saturated sodium chloride solution, dried with magnesium sulfate and concentrated under reduced pressure to give (E)-3-[5-(4-methylphenyl)-thiophen-2-yl]acrylic acid (1.9 g) as yellow crystals.

Provenance & Evidence