World Library  
Flag as Inappropriate
Email this Article

Propionaldehyde

Article Id: WHEBN0030872048
Reproduction Date:

Title: Propionaldehyde  
Author: World Heritage Encyclopedia
Language: English
Subject: Ethylene, Homochirality, Formaldehyde, Acetaldehyde, Methylglyoxal
Collection: Aldehydes, Hazardous Air Pollutants
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Propionaldehyde


Propionaldehyde or propanal is the aldehyde and is a structural isomer of acetone. It is a colourless liquid with a slightly irritating, fruity odour.

Contents

  • Production 1
    • Laboratory preparation 1.1
  • Uses 2
  • Interstellar occurrence 3
  • References 4

Production

Propionaldehyde is mainly produced industrially through hydroformylation, by combining synthesis gas (carbon monoxide and hydrogen) with ethylene using a metal (typically rhodium) catalyst:

CO + H2 + C2H4 → CH3CH2CHO

In this way, several hundred thousand tons are produced annually.[1]

Laboratory preparation

Propionaldehyde may also be prepared by oxidizing propanol with a mixture of sulfuric acid and potassium dichromate. The reflux condenser contains water heated at 60 °C, which condenses unreacted propanol, but allows propionaldehyde to pass. The propionaldehyde vapor is immediately condensed into a suitable receiver. In this arrangement, any propionaldehyde formed is immediately removed from the reactor, thus it does not get over-oxidized to propionic acid.[2]

Uses

It is principally used as a precursor to trimethylolethane (CH3C(CH2OH)3) through a condensation reaction with formaldehyde; this triol is an important intermediate in the production of alkyd resins. Other applications include reduction to propanol and oxidation to propionic acid.[1]

Condensation of propionaldehyde with imine with LDA produces CH3CHLiCH=N-t-Bu, which in turn condenses with aldehydes.[3]

Interstellar occurrence

Astronomers have detected propionaldehyde in the molecular cloud Sagittarius B2 near the center of the Milky Way Galaxy, about 26,000 light years from Earth.[4][5][6] Because molecules emit energy at specific frequencies, researchers were able to identify propionaldehyde and the related compound, acrolein, by measuring radio waves emitted by the cloud.

References

  1. ^ a b Anthony J. Papa "Propanal" In Ullmann's Encyclopedia of Industrial Chemistry, 2011, WIley-VCH, Weinheim. doi:10.1002/14356007.a22_157.pub2
  2. ^ Charles D. Hurd and R. N. Meinert (1943), "Propionaldehyde",  
  3. ^ Peralta, M. M. "Propionaldehyde t-Butylimine" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. doi:10.1002/047084289.
  4. ^ Scientists Discover Two New Interstellar Molecules: Point to Probable Pathways for Chemical Evolution in Space, National Radio Astronomy Observatory, June 21, 2004
  5. ^ Two newly found space molecules. By: Goho, Alexandra, Science News, 00368423, 7/24/2004, Vol. 166, Issue 4
  6. ^ Chemical Precursors to Life Found in Space Scientists say that a universal prebiotic chemistry may be at work
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 



Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.