A cyanide-catalyzed imino-Stetter reaction enables the concise total syntheses of rucaparib

Jinjae Park, Cheol Hong Cheon

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


Two routes toward the synthesis of rucaparib, an FDA-approved drug used for the treatment of ovarian and prostate cancers, have been developed from commercially available starting materials utilizing the cyanide-catalyzed imino-Stetter reaction as the key step for the construction of the indole motif bearing all the desired substituents in their correct positions. In the first-generation synthesis, meta-fluorobenzoate, the starting material currently used in the process chemistry route of rucaparib, was converted into 4,6-disubstituted 2-aminocinnamic acid derivatives (ester or amide). The cyanide-catalyzed imino-Stetter reaction of aldimines derived from the resulting 2-aminocinnamic acid derivatives and a commercially available aldehyde afforded the desired indole-3-acetic acid derivatives. The final azepinone formation completed the total synthesis of rucaparib in 27% overall yield. To resolve the issues raised in the first-generation synthesis, we further developed a second-generation synthesis of rucaparib. The Heck reaction of a commercially available ortho-iodoaniline derivative with acrylonitrile provided 4,6-disubstituted 2-aminocinnamonitrile, which was subjected to the imino-Stetter reaction with the same aldehyde to provide the desired indole-3-acetonitrile product. Subsequent construction of the azepinone scaffold completed the total synthesis of rucaparib in 59% overall yield over three separation operations. The synthetic strategy reported herein can provide a highly practical route to access rucaparib from commercially available starting materials (5.2% overall yield in the current process chemistry route vs. 59% overall yield in the second-generation synthesis).

Original languageEnglish
Pages (from-to)21172-21180
Number of pages9
JournalRSC Advances
Issue number33
Publication statusPublished - 2022 Aug 1

Bibliographical note

Funding Information:
This work was supported by the National Research Foundation of Korea (NRF) grants funded by the Korean Government (NRF-2021R1A2C1012984, NRF-2021R1A5A6002803 (Center for New Directions in Organic Synthesis).

Publisher Copyright:
© 2022 The Royal Society of Chemistry.

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)


Dive into the research topics of 'A cyanide-catalyzed imino-Stetter reaction enables the concise total syntheses of rucaparib'. Together they form a unique fingerprint.

Cite this