Oxidation of alcohols Addition of a primary or secondary alcohol to a solution of oxalyl chloride in
DMSO, followed by quenching with an organic base such as
triethylamine converts
alcohols to the corresponding
aldehydes and
ketones via the process known as the
Swern oxidation.
Synthesis of acyl chlorides Oxalyl chloride is mainly used together with a
N,N-dimethylformamide catalyst in
organic synthesis for the preparation of acyl chlorides from the corresponding
carboxylic acids. Like
thionyl chloride, the reagent degrades into volatile side products in this application, which simplifies workup. One of the minor byproducts from the
N,
N-dimethylformamide catalyzed reaction,
dimethylcarbamoyl chloride, is a potent carcinogen, stemming from the
N,
N-dimethylformamide decomposition. Relative to thionyl chloride, oxalyl chloride tends to be a milder, more selective
reagent. It is also more expensive than
thionyl chloride so it tends to be used on a smaller scale. : This reaction involves conversion of
N,
N-dimethylformamide to the
imidoyl chloride derivative (chloromethylene(dimethyl)ammonium ion ), akin to the first stage in the
Vilsmeier–Haack reaction. The imidoyl chloride is the active chlorinating agent.
Addition of carboxylic acid groups to arenes Oxalyl chloride reacts with
aromatic compounds in the presence of
aluminium chloride to give the corresponding
acyl chloride in a process known as a
Friedel-Crafts acylation. The resulting acyl chloride can be hydrolysed to form the corresponding
carboxylic acid.
Preparation of oxalate diesters Like other acyl chlorides, oxalyl chloride reacts with alcohols to give esters: : Typically, such reactions are conducted in the presence of a base such as
pyridine. The diester derived from
phenol,
phenyl oxalate ester, is Cyalume, the active ingredient in
glow sticks. A similar reaction occurs with
amines to give substituted
oxalamides: :
Other Oxalyl chloride was reportedly used in the first synthesis of
dioxane tetraketone (), an
oxide of carbon. ==Precautions==