SYNTHESIS OF 3,4-DIHYDROXY-6-(N-ETHYLAMINO)BENZAMIDE, A NEW PHENOLIC COMPOUND ISOLATED FROM GREEN-PEPPER (PIPER-NIGRUM L) BERRIES

The synthesis of 3,4-dihydroxy-6-(N-ethylamino)-benzamide (9), a novel phenolic constituent of green. pepper berries, responsible for its bl ackening during drying process has been developed from vanillic acid ( 1) in eight steps. Use of mild reaction conditions such as employing a nhydrous ammonium formate as hydrogen transfer agent during reduction of 3 at room temperature (Step III), reductive alkylation of 4 with so dium borohydride and acetic acid (Step IV) and protecting the amino gr oup using trifluoroacetic acid prior to demethylation (Step VII) and h ydrolysis (Step VIII) results in an acceptable yield of the final prod uct (9) despite its highly unstable nature.