Synthesis of indole analogues of the anti-Helicobacter pylori compounds CJ-13,015, CJ-13,102, CJ-13,104 and CJ-13,108

Racemic syntheses of indole analogues of four phthalide-containing anti-Helicobacter pylori agents CJ-13,015, CJ-13,102, CJ-13,104 and CJ-13,108 are reported via manipulation of a common intermediate. This intermediate was formed by the N-alkylation of 4,6-dimethoxyindole with a long chain bromide followed by further chain extension. Oxidation, acetylation, or Barton-McCombie deoxygenation of the intermediate followed by Wacker oxidation afforded three analogues whilst further reduction of one analogue afforded the final analogue.