3-Benzyloxycinnamic acid

1026884-98-9

122024-75-3

General procedure for the synthesis of 3-(3-(benzyloxy)phenyl)acrylic acid from (E)-3-(3-hydroxyphenyl)acrylic acid (CAS:1026884-98-9, 100 g, 606 mmol): the raw material was added into a 2L jacketed reactor, and after displacing the air in the reactor with nitrogen, 800 mL of anhydrous DMF was added to start the stirring. Under the condition of controlling the reaction temperature of 20℃-30℃, solid potassium carbonate (250g, 1.81mol) was added in batches. Subsequently, benzyl bromide (160 mL, 1.35 mol) was added and the reaction mixture was stirred at 35 °C for 4 h until the conversion of the bisbenzyl adduct exceeded 95%. Upon completion of the reaction, it was cooled to 22 °C, diluted with 1200 mL of water, further cooled to 10 °C and 800 mL of water was slowly added over 100 min. After stirring for 1 hour, the solid product was collected by filtration and washed with water. The wet solid was reloaded into a 2L jacketed reactor, 650mL of ethanol was added and heated to 55°C. At this temperature, 2M aqueous sodium hydroxide solution (790mL) was added and stirring was continued for 45 minutes until the saponification reaction was more than 98% complete. After cooling to room temperature, the target product was induced to crystallize by dropwise addition of 3M aqueous HCl solution (600 mL) over 70 minutes at 70°C. After stirring for 1 to 18 hours at room temperature, the solid was collected by filtration and washed sequentially with water and heptane. Finally, the solid was placed in a vacuum oven and dried with a stream of nitrogen at 50 °C for 18 h to afford (E)-3-(3-(benzyloxy)phenyl)acrylic acid as a white solid (151.24 g, purity 100 wt%, yield 98%). The product was characterized by 1H NMR (400 MHz, CDCl3): δ 7.75 (d, J = 15.84 Hz, 1H), 7.47-7.28 (m, 6H), 7.19-7.14 (m, 2H), 7.03 (d, J = 8.1 Hz, 1H), 6.43 (d, J = 16.1 Hz, 1H), 5.10 (s, 2H).