|Preferred IUPAC name
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||58.080 g·mol−1|
|Density||0.81 g cm−3|
|Melting point||−81 °C (−114 °F; 192 K)|
|Boiling point||46 to 50 °C (115 to 122 °F; 319 to 323 K)|
|20 g/100 mL|
|Viscosity||0.6 cP at 20 °C|
|C1, O: sp2
C2, C3: sp3
|H225, H302, H315, H318, H332, H335|
|P210, P261, P280, P304+P340+P312, P305+P351+P338, P310, P403+P235|
|NFPA 704 (fire diamond)|
|Flash point||−26 °C (−15 °F; 247 K)|
|175 °C (347 °F; 448 K)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|(what is ?)|
Propionaldehyde or propanal is the organic compound with the formula CH3CH2CHO. It is the 3-carbon aldehyde. It is a colourless, flammable liquid with a slightly fruity odour. It is produced on a large scale industrially.
In this way, several hundred thousand tons are produced annually.
Propionaldehyde may also be prepared by oxidizing 1-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.
Propionaldehyde exhibits the reactions characteristic of alkyl aldehydes, e.g. hydrogenation, aldol condensations, oxidations, etc. It is the simplest aldehyde with a prochiral methylene such that α-functionalized derivatives (CH3CH(X)CHO) are chiral.
It is predominantly 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. It is used in the synthesis of several common aroma compounds (cyclamen aldehyde, helional, lilial). Other applications include reduction to propanol and oxidation to propionic acid.
Propionaldehyde is a common reagent, being a building block to many compounds. Many of these uses exploit its participation in condensation reactions.[verification needed] With tert-butylamine it gives CH3CH2CH=N-t-Bu, a three-carbon building block used in organic synthesis.
Measurements by the COSAC and Ptolemy instruments on comet 67/P's surface, revealed sixteen organic compounds, four of which were seen for the first time on a comet, including acetamide, acetone, methyl isocyanate and propionaldehyde.
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