Propionic anhydride is an
organic compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The ...
with the
formula (CH
3CH
2CO)
2O. This simple
acid anhydride An acid anhydride is a type of chemical compound derived by the removal of water molecules from an acid.
In organic chemistry, organic acid anhydrides contain the functional group R(CO)O(CO)R'. Organic acid anhydrides often form when one equivale ...
is a colourless liquid. It is a widely used
reagent in
organic synthesis as well as for producing specialty derivatives of cellulose.
[
]
Synthesis
Industrial route to propionic anhydride involves thermal dehydration, driving off the water by distillation:
:2 CH3CH2CO2H → (CH3CH2CO)2O + H2O
Another routes is the Reppe carbonylation of ethylene
Ethylene (IUPAC name: ethene) is a hydrocarbon which has the formula or . It is a colourless, flammable gas with a faint "sweet and musky" odour when pure. It is the simplest alkene (a hydrocarbon with carbon-carbon double bonds).
Ethylene i ...
with propionic acid and nickel carbonyl
Nickel carbonyl (IUPAC name: tetracarbonylnickel) is a nickel(0) organometallic compound with the formula Ni(CO)4. This colorless liquid is the principal carbonyl of nickel. It is an intermediate in the Mond process for producing very high-pu ...
as the catalyst:
:CH2=CH2 + CH3CH2CO2H + CO → (CH3CH2CO)2O
Propionic anhydride has also been prepared by dehydration of propionic acid using ketene
In organic chemistry, a ketene is an organic compound of the form , where R and R' are two arbitrary monovalent chemical groups (or two separate substitution sites in the same molecule). The name may also refer to the specific compound ethen ...
:
: 2 CH3CH2CO2H + CH2=C=O → (CH3CH2CO)2O + CH3CO2H
Safety
Propanoic anhydride is strong smelling and corrosive
A corrosive substance is one that will damage or destroy other substances with which it comes into contact by means of a chemical reaction.
Etymology
The word ''corrosive'' is derived from the Latin verb ''corrodere'', which means ''to gnaw'', ...
, and will cause burns on contact with skin. Vapour can burn eyes and lungs.
Legal Status
Due to its potential use as a precursor in the synthesis of fentanyl
Fentanyl, also spelled fentanil, is a very potent synthetic opioid used as a pain medication. Together with other drugs, fentanyl is used for anesthesia. It is also used illicitly as a recreational drug, sometimes mixed with heroin, cocain ...
and fentanyl analogs, propanoic anhydride is regulated by the United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
Drug Enforcement Administration
The Drug Enforcement Administration (DEA; ) is a Federal law enforcement in the United States, United States federal law enforcement agency under the U.S. Department of Justice tasked with combating drug trafficking and distribution within th ...
as a List I chemical under the Controlled Substances Act
The Controlled Substances Act (CSA) is the statute establishing federal government of the United States, federal drug policy of the United States, U.S. drug policy under which the manufacture, importation, possession, use, and distribution of ...
.Drugs of Abuse Publication, Chapter 2
References
{{Authority control
Carboxylic anhydrides
Lachrymatory agents