PTC‐Promoted Japp–Klingmann Reaction for the Synthesis of Indole Derivatives

作者：Wei He; Bang‐Le Zhang; Zhong‐Jie Li; Sheng‐Yong Zhang

来源：Synthetic Communications, 2005, 35(10): 1359-1368.

DOI：10.1081/SCC-200057274

• Aryl hydrazones
• Fischer indolization
• Japp–Klingmann reaction
• Phase‐transfer catalysts

Indole derivatives have been efficiently synthesized from ethyl 2‐phenylhydrazono‐5‐phthalimido‐pentanoate and its derivatives, which were obtained by Japp–Klingmann reaction under phase‐transfer catalytic (PTC) conditions. Several different phase‐transfer catalysts were investigated and dimethyldioctadecyl ammonium chloride (DMDOA) was found to promote this reaction efficiently. Using DMDOA as the PTC, aryl hydrazones were obtained in yields of 90%. The pure aryl hydrazones were then efficiently cyclized to indole derivatives in yields of more than 80%.

• 单位
  第四军医大学; 西北大学