Page 178 - Chemical and process design handbook

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CAFFEINE, THEOBROMINE,

AND THEOPHYLLINE

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Caffeine (melting point: 238 C, sublimes at 178 C; density: 1.23), theo-
bromine, and theophylline are xanthine derivatives classified as central
nervous stimulants, but differing markedly in their properties. They can be
extracted from a number of natural sources.
Caffeine has been isolated from waste tea and from the decaffeiniza-
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tion of coffee by extraction at 70 C, using rotating countercurrent drums
and an organic solvent, frequently trichloroethylene. The solvent is
drained off, and the beans steamed to remove residual solvent. The extrac-
tion solvent is evaporated, and the caffeine is hot-water-extracted from the
wax, decolorized with carbon, and recrystallized.
Caffeine is also manufactured synthetically by, for instance, the methy-
lation of theobromine and also total synthesis by methylation and other
reactions based upon urea.
Caffeine is used by the pharmaceutical industry and also by the soft-
drink industry for cola-style drinks.

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