3-(3,4-Dihydroxyphenyl)Prop-2-Enoic Acid → Caffeic Acid

Participants

Reaction Conditions

Reaction Steps

3,4-Dihydroxycinnamic acid (1.13 g, 6.27 mmole) was dissolved in thionyl chloride (25 ml) and the solution was stirred for 5 hours at 40-60° C. The solvent was removed, the residue was dissolved in thoroughly dried ethyl acetate and the solution was slowly added to a solution of 5-methoxy tryptamine (1.2 g) in benzene, which contained also ethylamine (1 ml). The mixture was stirred overnight, water (10 ml) was added and the mixture again stirred for 15 minutes. The solvents were removed, the residue was dissolved in ethyl acetate and the solution was washed successively with water, saturated NaHCO3 solution, water and brine, and then dried over Na2SO4. The solvent was removed and the product was purified by column chromatography using 1:9 methanol/dichloromethane. The purification process was repeated three times to remove byproducts. The fraction identified as the caffeic acid 5-methoxytryptamide was further purified by recrystallization from ethyl acetate/hexane solution. The compound was obtained as white crystals (yield about 60%).

Provenance & Evidence