Synthesis of(E)-3-(3,4-dihydroxyphenyl) acrylic acid

(E)-3-(3,4-Dihydroxyphenyl)acrylic acid was prepared from 3,4-dimethoxybenzaldehyde via the Knoevenagel reaction and demethylation.The first step was activated by microwave radiation and the second step reacted in the system of TMSCl/NaI/CH_3CN.The optimum conditions of the two steps were studied.The structural characterization of the final product was investigated by IR spectrum,(()~1HNMR) and elemental analysis.The overall yield was 90%.