An alternative synthesis of 10<i>H</i>‐indolo[3,2‐<i>b</i>]quinoline and its selective <i>N</i>‐alkylation

Abstract

Abstract A new and a more efficient synthesis of 10 H ‐Indolo[3,2‐ b ]quinoline (quindoline) is reported. The synthesis involved N ‐arylation of 3‐aminoquinoline with triphenylbismuth diacetate followed by oxidative cyclization using paOadium(II) acetate. A selective N ‐alkylation methodology for quindoline was also developed. Alkylation on N‐5 was obtained in sulpholane, while alkylation on N‐10 was achieved in acetone in the presence of potassium hydroxide. A sequential N‐5‐ and N‐10 double alkylation procedure was also formulated.