Propionic anhydride

<h2 id="synthesis">Synthesis</h2>
<p>Industrial route to propionic anhydride involves thermal dehydration of <a href="/facts/Propionic_acid/ugBEw0Ia">propionic acid</a>, driving off the water by distillation:
</p>
2 CH3CH2CO2H  →  (CH3CH2CO)2O  +  H2O
<p>Another routes is the <a href="/facts/Reppe_carbonylation/Jq8jghNR">Reppe carbonylation</a> of <a href="/facts/Ethylene/QMNBYLYn">ethylene</a> with propionic acid and <a href="/facts/Nickel_carbonyl/8Py5Dre1">nickel carbonyl</a> as the catalyst:<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a>
</p>
CH2=CH2  + CH3CH2CO2H +  CO →  (CH3CH2CO)2O
<p>Propionic anhydride has also been prepared by dehydration of propionic acid using <a href="/facts/Ketene/ByPehuE4">ketene</a>:<a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a> 
</p>
2 CH3CH2CO2H  +  CH2=C=O  →  (CH3CH2CO)2O  +  CH3CO2H
<h2 id="safety">Safety</h2>
<p>Propanoic anhydride is strong smelling and <a href="/facts/Corrosive/7LXjT1XE">corrosive</a>, and will cause burns on contact with skin. Vapour can <a href="/facts/Lachrymatory_agent/SLJoBYEN">burn eyes</a> and lungs.
</p>
<h2 id="legal-status">Legal Status</h2>
<p>Due to its potential use as a precursor in the synthesis of <a href="/facts/Fentanyl/MMD9GdD3">fentanyl</a> and fentanyl analogs, propanoic anhydride is regulated by the <a href="/facts/United_States/P0sCdLe5">United States</a> <a href="/facts/Drug_Enforcement_Administration/qGQpHNB8">Drug Enforcement Administration</a> as a List I chemical under the <a href="/facts/Controlled_Substances_Act/8laeNsgD">Controlled Substances Act</a>.<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a>
</p>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>Samel, Ulf-Rainer; Kohler, Walter; Gamer, Armin Otto; Keuser, Ullrich (2005). "Propionic Acid and Derivatives". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a22_223. ISBN 978-3-527-30673-2. <a href="978-3-527-30673-2" target="_blank">978-3-527-30673-2</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>Samel, Ulf-Rainer; Kohler, Walter; Gamer, Armin Otto; Keuser, Ullrich (2005). "Propionic Acid and Derivatives". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a22_223. ISBN 978-3-527-30673-2. <a href="978-3-527-30673-2" target="_blank">978-3-527-30673-2</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
<li id="fn:3"><p>Williams, J. W. Krynitsky, J. A. (1941). "n-Caproic Anhydride". Organic Syntheses. 21: 13. doi:10.15227/orgsyn.021.0013{{cite journal}}:  CS1 maint: multiple names: authors list (link). <a href="/wiki/Organic_Syntheses" target="_blank">/wiki/Organic_Syntheses</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li>
<li id="fn:4"><p>Drugs of Abuse Publication, Chapter 2 Archived 2007-12-20 at the Wayback Machine <a href="https://www.dea.gov/pubs/abuse/2-chem.htm" target="_blank">https://www.dea.gov/pubs/abuse/2-chem.htm</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li>
</ol>

Propionic anhydride open-in-new

Propionic anhydride