Ps. Variyar et C. Bandyopadhyay, SYNTHESIS OF 3,4-DIHYDROXY-6-(N-ETHYLAMINO)BENZAMIDE, A NEW PHENOLIC COMPOUND ISOLATED FROM GREEN-PEPPER (PIPER-NIGRUM L) BERRIES, Indian journal of chemistry. Sect. B: organic chemistry, including medical chemistry, 34(10), 1995, pp. 911-913
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.