Acetyl iodide is an
organoiodine compound
Organoiodine compounds are organic compounds that contain one or more carbon–iodine bonds. They occur widely in organic chemistry, but are relatively rare in nature. The thyroxine hormones are organoiodine compounds that are required for he ...
with the
formula
In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwee ...
CH
3COI. It is a colourless liquid. It is formally derived from
acetic acid
Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main component ...
. Although far rarer in the laboratory than the related
acetyl bromide
Acetyl bromide is an acyl bromide compound. As is expected, it may be prepared by reaction between phosphorus tribromide and acetic acid:
: 3 CH3COOH + PBr3 → 3 CH3COBr + H3PO3
As usual for an acid halide, acetyl bromide hydrolyzes rapidly i ...
and
acetyl chloride
Acetyl chloride (CH3COCl) is an acyl chloride derived from acetic acid. It belongs to the class of organic compounds called acid halides. It is a colorless, corrosive, volatile liquid. Its formula is commonly abbreviated to AcCl.
Synthesis
On a ...
, acetyl iodide is produced, transiently at least, on a far larger scale than any other acid halide. Specifically, it is generated by the
carbonylation
Carbonylation refers to reactions that introduce carbon monoxide into organic and inorganic substrates. Carbon monoxide is abundantly available and conveniently reactive, so it is widely used as a reactant in industrial chemistry. The term carbon ...
of
methyl iodide in the
Cativa and
Monsanto process
The Monsanto process is an industrial method for the manufacture of acetic acid by catalytic carbonylation of methanol. The Monsanto process has largely been supplanted by the Cativa process, a similar iridium-based process developed by BP Chemic ...
es, which are the main industrial processes that generate
acetic acid
Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main component ...
.
It is also an intermediate in the production of acetic anhydride from
methyl acetate
Methyl acetate, also known as MeOAc, acetic acid methyl ester or methyl ethanoate, is a carboxylate ester with the formula CH3COOCH3. It is a flammable liquid with a characteristically pleasant smell reminiscent of some glues and nail polish remo ...
.
Upon treatment with carboxylic acids, acetyl iodide does not exhibit reactions typical of
acyl halides, such as acetyl chloride. Instead, acetyl iodide undergoes iodide/hydroxide exchange with most
carboxylic acid
In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an R-group. The general formula of a carboxylic acid is or , with R referring to the alkyl, alkenyl, aryl, or other group. Carboxylic ...
s:
:
References
{{Reflist
Acyl iodides