(e)-n-(2-(3,4-dihydroxyphenyl)ethyl)-3-(4-hydroxyphenyl)-2-propenaMide

3943-97-3

645-31-8

106005-97-4

General procedure for the synthesis of N-coumaroyldopamine (CAS:106005-97-4) from methyl 4-hydroxycinnamate and 2-(3,4-dihydroxyphenyl)ethylamine: 14.2 g of dopamine hydrobromide, 9.0 g of methyl p-hydroxycinnamate, 5.1 g of sodium bicarbonate, and 50 mL of N-methyl pyrrolidone were added to 100 mL of a four-necked round-bottomed flask. The reaction mixture was heated to 160 °C under nitrogen protection and maintained for 12 h. The progress of the reaction was monitored by TLC. Upon completion of the reaction, 200 mL of water was added to the mixture and extracted with ethyl acetate (100 mL x 3). The organic phases were combined and washed sequentially with saturated brine (100 mL × 2) and 1N dilute hydrochloric acid (100 mL × 2). The organic phase was dried with anhydrous sodium sulfate, filtered and concentrated to give 28.0 g of slurry. To the slurry was added 20 mL of petroleum ether and 2 mL of ethyl acetate and heated to reflux for 30 min. After cooling, it was allowed to stand and the upper solution was poured out. To the remaining slurry, 10 mL of anhydrous ethanol was added, stirred for 30 min, filtered and dried to give 10.2 g of white solid product. The product was identified as N-coumaroyldopamine by NMR. This method can obtain a high purity product without column chromatography purification, and the yield can be up to 67%.