HPLC Determination of (E)-3-Ethyl-(2,3-Dihydro-1-Benzofuran-5-yl)-2-Propenoate and Its by-Products in the Process of Synthesis

A method for the determination of (E)-3-ethyl-(2,3-dihydro-1-benzofuran-5-yl)-2-propenoate abbreviated as (E)-EDHBFP and its by-products during synthesis by HPLC was proposed.The Diamonsil-C18 column (250 mm×4.6 mm,5 μm) was used as the stationary phase,and a mixture of methanol and water (72+28 by vol.) was used as the mobile phase,with its flow-rate at 0.8 mL·min-1.UV detection at the wavelength of 319 nm was adopted in the determination.It was found that under the optimum condition of the proposed method,the objective product (E)-EDHBFP was well separated from the reactant of synthesis (i.e.,2,3-dihydro-1-benzofuran-5-carbaldehyde),and the isomeric by-product (Z)-3-ethyl-(2,3-dihydro-1-benzofuran-5-yl)-2-propenoate as well as an unknown by-product as shown in the chromatogram.Linear relationship between values of peak area and concentration of (E)-EDHBFP was obtained in the range of 10-80 mg·L-1 with the value of detection limit (3S/N) of 35 μg·L-1.The proposed method was used for the quality control of synthesis of (E)-EDHBFP.