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.