ABSTRACT 1,2,3,4-tetrahydroquinoline and -isoquinoline derivatives were oxidatively aromatized to the corresponding quinolines or isoquinolines and oxygenated to the corresponding quinolines or isoquinoline N-oxides in moderate yields using molecular oxygen as an oxidant and sodium tungstate as a catalyst in the presence of activated carbon in MeOH or xylenes. The present oxidation process revealed the importance of activated carbon, without which the oxidation would not proceed. Additionally, it serves as an example of an environmentally benign oxidative process conducted using molecular oxygen in place of harmful metal oxidants like CrO3, Pb(OAc)4, or Hg(OAc)2.
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