Hydroxyphenylacetic acid → 3-(3,5-Dimethylphenyl)-2-(4-hydroxyphenyl)-acrylic acid

Participants

Reaction Steps

To a mixture of 43 (3.23 g, 24 mmol), 4-hydroxyphenylacetic acid (3.66 g, 24 mmol) and potassium acetate (2.83 g, 28 mmol) was added acetic anhydride (100 mL). The mixture was heated to reflux for 4 h, cooled to room temperature, and then poured over water (400 mL). After stirring for 1.5 h, a solid gum settled to the bottom and the supernatant was decanted. To the residue was added THF (100 mL) and 1N NaOH (150 mL) and the mixture was stirred for 30 min. The mixture was acidified with 1N HCl (200 mL) and the product was extracted into ethyl acetate (300 mL), washed with water (300 mL), brine (300 mL), dried (MgSO4), filtered and concentrated in vacuo. The crude solid was crystallized in toluene to yield 2.65 g (42%) of a pale yellow solid 44.

Provenance & Evidence