Synthesis of Labeled Caffeine - Caffeine: Chemistry, Analysis, Function and Effects - page 72

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CHAPTER 5
Synthesis of Labeled Caffeine

FR ´ D ´ RIC BALSSA

Laboratoire des Courses Hippiques, 15 rue de Paradis, ZAC Pompidou,
91370 Verri`res le Buisson, France
E-mail: [e-mail]

5.1 Introduction
This chapter presents an overview of strategies and methods used for the
preparation of labeled caffeine. Due to its specific physico-chemical properties,
the use of labeled caffeine constitutes a powerful analytical tool with

applications in various fields of biology, pharmacology, medicine and

botanics.
Stable isotope labeled caffeine exhibits a mass difference with native caffeine
which can easily be evidenced by mass spectrometry. If the introduced isotope
is unstable, the native molecule or its metabolites become radioactive and can
therefore be detected by appropriate b-radiation spectrometry.
The numerous applications of labeled caffeine made its synthesis of
particular interest. Since each specific application requires a proper choice of
the isotope nature as well as the number and the location of labeling sites,
chemists have developed various strategies for selective isotope introduction
into the caffeine molecule.

5.2 Strategies for Caffeine Labeling
Three synthetic strategies for the synthesis of labeled caffeine are now well
established: catalyzed exchange of hydrogen for deuterium or tritium, total