Introduction
<P>The title compound oxalic acid is available in anhydrous and dihydrate forms and
exhibits several features which have made it particularly attractive as a reagent
in organic synthesis. Oxalic acid is a mild Brønsted acid, which finds application
in the Beckmann reaction,
[
1]
protection and deprotection of carbonyl compounds,
[
2-4]
and various selective cleavage and hydrolytic reactions. It is frequently used as
a mild acidic quench for a variety of reactions including oxidations.
[
5]
Oxalic acid has also been used as an acidic agent in a number of condensation processes
such as condensation of allylic alcohols with aromatic rings,
[
6]
carbonyl compounds and hydrazines,
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7]
aromatic amines and aldehydes,
[
8]
and it has been utilized as a bifunctional condensation partner in the synthesis of
heterocyclic systems.
[
9]
</P><P>Oxalic acid is the simplest of the dicarboxylic acids and is widely used in
inorganic chemistry as a precipitant and chelating agent (oxalate as a bidentate ligand
has been of great interest in coordination chemistry).
[
10]
</P>
