Sodium Bicarbonate → Phenethyl (E)-caffeate

Temperature

150 °C

1 g of caffeic acid was dissolved in 20 mL of ethanol and 2 mL water. 0.5 g of sodium bicarbonate was added while stirring. Stirring continued for 3 hr. Solvent and water were distilled off under vacuum. The residual solid was dissolved in 25 mL dimethylformamide and heated to 150° C. To this hot reaction mixture 0.8 mL of phenethyl bromide was added. The resulting reaction mixture was stirred for 40 hrs. Next, the reaction mixture was poured into 75 mL of cold water and extracted with ether (3×70 mL). The combined organic extract was washed with 50 mL of 5% HCl and water (60 mL). After drying over sodium sulfate, the solvent was distilled off under vacuum. The residue was crystallized from toluene by treatment with activated carbon to obtain caffeic acid phenethyl ester. The yield was 304 mg and the purity was greater than 90%.

1. stirringStirring
2. distillationSolvent and water were distilled off under vacuum
3. dissolutionThe residual solid was dissolved in 25 mL dimethylformamide
4. additionTo this hot reaction mixture 0.8 mL of phenethyl bromide was added
5. customThe resulting reaction mixture
6. stirringwas stirred for 40 hrs
7. extractionextracted with ether (3×70 mL)
8. extractionThe combined organic extract
9. washwas washed with 50 mL of 5% HCl and water (60 mL)
10. dry with materialAfter drying over sodium sulfate
11. distillationthe solvent was distilled off under vacuum
12. customThe residue was crystallized from toluene by treatment with activated carbon

ORD record

ord-b772752bfcb846cb9159c02a6f541f18

Source dataset

uspto-grants-2008_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07368593B1