Propionaldehyde

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Propionaldehyde
Skeletal formula of propionaldehyde (propanal) Skeletal formula of propionaldehyde.svg
Skeletal formula of propionaldehyde (propanal)
Flat structure Propionaldehyde flat structure.png
Flat structure
Propionaldehyde-3D-balls.png
Propionaldehyde.jpg
Names
IUPAC name
Propionaldehyde
Preferred IUPAC name
Propanal
Other names
  • Methylacetaldehyde
  • Propionic aldehyde
  • Propaldehyde
  • Propan-1-one
Identifiers
3D model (JSmol)
3DMet
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.004.204 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 204-623-0
KEGG
PubChem CID
RTECS number
  • UE0350000
UNII
UN number 1275
  • InChI=1S/C3H6O/c1-2-3-4/h3H,2H2,1H3 Yes check.svgY
    Key: NBBJYMSMWIIQGU-UHFFFAOYSA-N Yes check.svgY
  • CCC=O
Properties
C3H6O
Molar mass 58.080 g·mol−1
AppearanceColourless liquid
Odor Pungent and fruity
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
-34.32·10−6 cm3/mol
Viscosity 0.6 cP at 20 °C
Structure
C1, O: sp2

C2, C3: sp3

2.52 D
Hazards
GHS labelling:
GHS-pictogram-flamme.svg GHS-pictogram-acid.svg GHS-pictogram-exclam.svg
Danger
H225, H302, H315, H318, H332, H335 [1]
P210, P261, P280, P304+P340+P312, P305+P351+P338, P310, P403+P235 [1]
NFPA 704 (fire diamond)
NFPA 704.svgHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g. gasolineInstability 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g. white phosphorusSpecial hazards (white): no code
2
3
2
Flash point −26 °C (−15 °F; 247 K)
175 °C (347 °F; 448 K)
Related compounds
Related aldehydes
Acetaldehyde
Butyraldehyde
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

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 pungent and fruity odour. It is produced on a large scale industrially.

Contents

Production

Propionaldehyde is mainly produced industrially by hydroformylation of ethylene:

CO + H2 + C2H4 → CH3CH2CHO

In this way, several hundred thousand tons are produced annually. [2]

Laboratory preparation

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. [3]

Reactions

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. If water is available, propionaldehyde exists in equilibrium with 1,1-propanediol, a geminal diol.

Uses

Both industrially and in the laboratory, propionaldehyde has primary application as a chemical building block. [2] :4 [4]

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). [2]

Reduction of propionaldehyde gives npropanol, and reductive amination gives propanamine. Rising demand for non-chlorocarbon solvents has caused some manufacturers to substitutively brominate npropanol to propyl bromide. However, the majority of applications use npropanol proper in esters or glycol ethers, or as a gentle alkylant for primary and secondary amines. [2] :5

Oxidants instead give propionic acid and propionates, typically used as preservatives. [2] :5

Laboratory uses

Many laboratory uses exploit its participation in condensation reactions. [5] [ better source needed ] With tert-butylamine it gives CH3CH2CH=N-t-Bu, a three-carbon building block used in organic synthesis. [6]

Extraterrestrial occurrence

Propionaldehyde along with acrolein has been detected in the molecular cloud Sagittarius B2 near the center of the Milky Way Galaxy, about 26,000 light years from Earth. [7] [8] [9]

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. [10] [11] [12]

Safety

With an LD50 of 1690 mg/kg (oral), [2] propionaldehyde exhibits low acute toxicity, but is a lung and eye irritant and is a combustible liquid.

Related Research Articles

<span class="mw-page-title-main">Ketone</span> Organic compounds of the form >C=O

In organic chemistry, a ketone is an organic compound with the structure R−C(=O)−R', where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group −C(=O)−. The simplest ketone is acetone, with the formula (CH3)2CO. Many ketones are of great importance in biology and industry. Examples include many sugars (ketoses), many steroids, and the solvent acetone.

<span class="mw-page-title-main">Hydrazone</span> Organic compounds - Hydrazones

Hydrazones are a class of organic compounds with the structure R1R2C=N−NH2. They are related to ketones and aldehydes by the replacement of the oxygen =O with the =N−NH2 functional group. They are formed usually by the action of hydrazine on ketones or aldehydes.

A diol is a chemical compound containing two hydroxyl groups. An aliphatic diol may also be called a glycol. This pairing of functional groups is pervasive, and many subcategories have been identified. They are used as protecting groups of carbonyl groups, making them essential in synthesis of organic chemistry.

<span class="mw-page-title-main">Imine</span> Organic compound or functional group containing a C=N bond

In organic chemistry, an imine is a functional group or organic compound containing a carbon–nitrogen double bond. The nitrogen atom can be attached to a hydrogen or an organic group (R). The carbon atom has two additional single bonds. Imines are common in synthetic and naturally occurring compounds and they participate in many reactions.

In organic chemistry, an acyl chloride is an organic compound with the functional group −C(=O)Cl. Their formula is usually written R−COCl, where R is a side chain. They are reactive derivatives of carboxylic acids. A specific example of an acyl chloride is acetyl chloride, CH3COCl. Acyl chlorides are the most important subset of acyl halides.

<span class="mw-page-title-main">Diazomethane</span> Simplest diazo compound and methylating agent

Diazomethane is an organic chemical compound with the formula CH2N2, discovered by German chemist Hans von Pechmann in 1894. It is the simplest diazo compound. In the pure form at room temperature, it is an extremely sensitive explosive yellow gas; thus, it is almost universally used as a solution in diethyl ether. The compound is a popular methylating agent in the laboratory, but it is too hazardous to be employed on an industrial scale without special precautions. Use of diazomethane has been significantly reduced by the introduction of the safer and equivalent reagent trimethylsilyldiazomethane.

Acetamide (systematic name: ethanamide) is an organic compound with the formula CH3CONH2. It is derived from acetic acid. It finds some use as a plasticizer and as an industrial solvent. The related compound N,N-dimethylacetamide (DMA) is more widely used, but it is not prepared from acetamide. Acetamide can be considered an intermediate between acetone, which has two methyl (CH3) groups either side of the carbonyl (CO), and urea which has two amide (NH2) groups in those locations. Acetamide is also a naturally occurring mineral with the IMA symbol: Ace.

<span class="mw-page-title-main">Nitro compound</span> Organic compound containing an −NO₂ group

In organic chemistry, nitro compounds are organic compounds that contain one or more nitro functional groups. The nitro group is one of the most common explosophores used globally. The nitro group is also strongly electron-withdrawing. Because of this property, C−H bonds alpha (adjacent) to the nitro group can be acidic. For similar reasons, the presence of nitro groups in aromatic compounds retards electrophilic aromatic substitution but facilitates nucleophilic aromatic substitution. Nitro groups are rarely found in nature. They are almost invariably produced by nitration reactions starting with nitric acid.

In organic chemistry, the Knoevenagel condensation reaction is a type of chemical reaction named after German chemist Emil Knoevenagel. It is a modification of the aldol condensation.

The Bouveault–Blanc reduction is a chemical reaction in which an ester is reduced to primary alcohols using absolute ethanol and sodium metal. It was first reported by Louis Bouveault and Gustave Louis Blanc in 1903. Bouveault and Blanc demonstrated the reduction of ethyl oleate and n-butyl oleate to oleyl alcohol. Modified versions of which were subsequently refined and published in Organic Syntheses.

<span class="mw-page-title-main">Potassium peroxymonosulfate</span> Chemical compound

Potassium peroxymonosulfate is widely used as an oxidizing agent, for example, in pools and spas. It is the potassium salt of peroxymonosulfuric acid. Usually potassium peroxymonosulfate is available as the triple salt 2KHSO5·KHSO4·K2SO4, known as Oxone.

<span class="mw-page-title-main">Knorr pyrrole synthesis</span> Chemical reaction

The Knorr pyrrole synthesis is a widely used chemical reaction that synthesizes substituted pyrroles (3). The method involves the reaction of an α-amino-ketone (1) and a compound containing an electron-withdrawing group α to a carbonyl group (2).

<i>o</i>-Phenylenediamine Chemical compound

o-Phenylenediamine (OPD) is an organic compound with the formula C6H4(NH2)2. This aromatic diamine is an important precursor to many heterocyclic compounds. OPD is a white compound although samples appear darker owing to oxidation by air. It is isomeric with m-phenylenediamine and p-phenylenediamine.

<span class="mw-page-title-main">Malononitrile</span> Organic compound with formula CH2(CN)2

Malononitrile is an organic compound nitrile with the formula CH2(CN)2. It is a colorless or white solid, although aged samples appear yellow or even brown. It is a widely used building block in organic synthesis.

<span class="mw-page-title-main">1,4-Benzoquinone</span> Chemical compound

1,4-Benzoquinone, commonly known as para-quinone, is a chemical compound with the formula C6H4O2. In a pure state, it forms bright-yellow crystals with a characteristic irritating odor, resembling that of chlorine, bleach, and hot plastic or formaldehyde. This six-membered ring compound is the oxidized derivative of 1,4-hydroquinone. The molecule is multifunctional: it exhibits properties of a ketone, being able to form oximes; an oxidant, forming the dihydroxy derivative; and an alkene, undergoing addition reactions, especially those typical for α,β-unsaturated ketones. 1,4-Benzoquinone is sensitive toward both strong mineral acids and alkali, which cause condensation and decomposition of the compound.

Salicylic aldehyde (2-hydroxybenzaldehyde) is an organic compound with the formula C6H4OH(CHO). Along with 3-hydroxybenzaldehyde and 4-hydroxybenzaldehyde, it is one of the three isomers of hydroxybenzaldehyde. This colorless oily liquid has a bitter almond odor at higher concentration. Salicylaldehyde is a precursor to coumarin and a variety of chelating agents.

<span class="mw-page-title-main">Lead(IV) acetate</span> Organometallic compound (Pb(C2H3O2)4)

Lead(IV) acetate or lead tetraacetate is an metalorganic compound with chemical formula Pb(C2H3O2)4. It is a colorless solid that is soluble in nonpolar, organic solvents, indicating that it is not a salt. It is degraded by moisture and is typically stored with additional acetic acid. The compound is used in organic synthesis.

<span class="mw-page-title-main">Isovaleraldehyde</span> Chemical compound

Isovaleraldehyde organic compound, also known as 3-methylbutanal, with the formula (CH3)2CHCH2CHO. It is an aldehyde, a colorless liquid at STP, and found in low concentrations in many types of food. Commercially it is used as a reagent for the production of pharmaceuticals, perfumes and pesticides.

Hydroxymethylation is a chemical reaction that installs the CH2OH group. The transformation can be implemented in many ways and applies to both industrial and biochemical processes.

α-Halo carboxylic acids and esters are organic compounds with the respective formulas RCHXCO2H and RCHXCO2R' where R and R' are organic substituents. The X in these compounds is a halide, usually chloride and bromide. These compounds are often used as intermediates in the preparation of more elaborate derivatives. They are often potent alkylating agents. The mono halide derivatives are chiral.

References

  1. 1 2 Record of Propanal in the GESTIS Substance Database of the Institute for Occupational Safety and Health, accessed on 22 March 2020.
  2. 1 2 3 4 5 6 Hensel, A. (2018). "Propanal". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi:10.1002/14356007.a22_157.pub3. ISBN   978-3527306732.
  3. Hurd, Charles D.; Meinert, R. N. (1932). "Propionaldehyde". Organic Syntheses. 12: 64. doi:10.15227/orgsyn.012.0064.
  4. Wehrli, Pius A.; Chu, Vera (1978). "Y-Ketoesters from Aldehydes Via Diethyl Acylsuccinates: Ethyl 4-Oxohexanoate". Organic Syntheses. 58: 79. doi:10.15227/orgsyn.058.0079.
  5. See, e.g., Sessler, Jonathan L.; Mozaffari, Azadeh; Johnson, Martin R. (1992). "3,4-Diethylpyrrole and 2,3,7,8,12,13,17,18-Octaethylporphyrin". Organic Syntheses . 70: 68. doi:10.15227/orgsyn.070.0068 .
  6. Peralta, M. M. "Propionaldehyde t-Butylimine" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. doi : 10.1002/047084289X.rp271.
  7. Scientists Discover Two New Interstellar Molecules: Point to Probable Pathways for Chemical Evolution in Space, National Radio Astronomy Observatory, June 21, 2004
  8. Two newly found space molecules. By: Goho, Alexandra, Science News, 00368423, 7/24/2004, Vol. 166, Issue 4
  9. Chemical Precursors to Life Found in Space Scientists say that a universal prebiotic chemistry may be at work
  10. Jordans, Frank (30 July 2015). "Philae probe finds evidence that comets can be cosmic labs". The Washington Post. Associated Press. Archived from the original on 23 December 2018. Retrieved 30 July 2015.
  11. "Science on the Surface of a Comet". European Space Agency. 30 July 2015. Retrieved 30 July 2015.
  12. Bibring, J.-P.; Taylor, M.G.G.T.; Alexander, C.; Auster, U.; Biele, J.; Finzi, A. Ercoli; Goesmann, F.; Klingehoefer, G.; Kofman, W.; Mottola, S.; Seidenstiker, K.J.; Spohn, T.; Wright, I. (31 July 2015). "Philae's First Days on the Comet - Introduction to Special Issue" (PDF). Science . 349 (6247): 493. Bibcode:2015Sci...349..493B. doi: 10.1126/science.aac5116 . PMID   26228139.