Recent Developments in Heterocycle Labeling With Carbon Isotopes

J Labelled Comp Radiopharm. 2018 Nov;61(13):988-1007. doi: 10.1002/jlcr.3666. Epub 2018 Jul 13.


Heterocycles play an essential role in modern pharmaceutical and agrochemical developments, representing a very common structural unit in marketed drugs. Over the 46 new drugs approved in 2017 by the FDA, 25 contain in their structure a heterocyclic core. The development of novel and straightforward labeling strategies for the effective insertion of carbon isotopes into heterocylic scaffolds is an inspiring and vibrant field of research. The use of carbon-11, carbon-13, and carbon-14 isotopes is well established in life science and particularly in pharmaceutical and agrochemical industry. Their introduction into small organic molecules represents a crucial step for the radiochemists. Because the labeling should occur in metabolically stable positions and in the shortest synthetic route, their incorporation into the heterocycles represents a viable solution. This review summarizes recent contributions to this area of research through the analysis of different industrial and academic cases.

Keywords: carbon-11; carbon-13; carbon-14; heterocycles; isotopic labeling.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Carbon Isotopes / chemistry*
  • Catalysis
  • Heterocyclic Compounds / chemistry*
  • Isotope Labeling / methods*


  • Carbon Isotopes
  • Heterocyclic Compounds