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Chapter 2
2.5.3 Condensation
[6, Ullmann, 2001, 16, Winnacker and Kuechler, 1982, 62, D1 comments, 2004]
See also Section 4.3.2.3 for environmental issues and treatment of waste streams from
condensation.
Condensation represents a widely applied reaction type in industrial organic chemistry. Some
examples are the manufacture of aromatic azo and poly azo compounds (intermediates for dyes
and pigments) or ring closures to give heterocyclic compounds (e.g. pyrazolones, indoles,
triazoles, pyrimidines, thiazoles).
Chemical reaction
A common feature of condensation reactions is the release of a molecule such as H2O or NH3
while the reactants are coupled, e.g:
R – COOH + R’ – NH2 � R – CO – NH – R’ + H2O
The removal of H2O is the key to shifting the equilibrium of the reaction to favour the target
product.
Operations
Because condensation reactions are diverse in nature, there is no universal method of carrying
them out. The production of each compound needs to be considered individually, taking into
account the chemical, engineering, and economic factors.
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