Pentanal (also called valeraldehyde) is the organic compound with molecular formula C4H9CHO. Classified as an alkyl aldehyde, it is a colorless volatile liquid. Its odor is described as fermented, bready, fruity, nutty, berry.[4]

Pentanal[1][2]
Structural formula of pentanal
Ball-and-stick model of the pentanal molecule
Names
Preferred IUPAC name
Pentanal
Other names
Pentanaldehyde
Valeraldehyde
Valeric aldehyde
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
DrugBank
ECHA InfoCard 100.003.442 Edit this at Wikidata
UNII
UN number 2058
  • InChI=1S/C5H10O/c1-2-3-4-5-6/h5H,2-4H2,1H3 ☒N
    Key: HGBOYTHUEUWSSQ-UHFFFAOYSA-N ☒N
  • InChI=1/C5H10O/c1-2-3-4-5-6/h5H,2-4H2,1H3
    Key: HGBOYTHUEUWSSQ-UHFFFAOYAJ
  • O=CCCCC
Properties
C5H10O
Molar mass 86.134 g·mol−1
Appearance Clear liquid
Odor Strong, acrid, pungent
Density 0.8095 at 20 °C
Melting point −60 °C (−76 °F; 213 K)
Boiling point 102 to 103 °C (216 to 217 °F; 375 to 376 K)
14 g/L (20 °C)
Vapor pressure 0.35 kPa (20 °C)[3]
Viscosity 0.6 mPa·s (20 °C)
Hazards
GHS labelling:
GHS02: FlammableGHS07: Exclamation mark
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 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 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
3
3
0
Flash point 12 °C (54 °F; 285 K)[3]
220 °C (428 °F; 493 K)
Lethal dose or concentration (LD, LC):
3200 mg/kg (oral, rat)
4860 mg/kg (dermal, rabbit)
14.3 ppm (rat, 4h)
NIOSH (US health exposure limits):
PEL (Permissible)
none[3]
REL (Recommended)
TWA 50 ppm (175 mg/m3)[3]
IDLH (Immediate danger)
N.D.[3]
Safety data sheet (SDS) Fisher Scientific
Related compounds
Related aldehydes
Butyraldehyde

Hexanal

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Production

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Pentanal is obtained by hydroformylation of butene. Also C4 mixtures can be used as starting material like the so-called raffinate II, which is produced by steam cracking and contains (Z)- and (E)-2-butene, 1-butene, butane and isobutane. The conversion to the product is accomplished with synthesis gas in the presence of a catalyst consisting of a rhodium-bisphosphite complex and a sterically hindered secondary amine with a selectivity toward pentanal of at least 90%.[5]

Pentanal undergoes the reactions characteristic of any alkyl aldehyde, i.e., oxidations, condensations, and reductions. 2-Octanone, produced for use in the fragrance industry, is obtained by the condensation of acetone and pentanal, followed by hydrogenation of the alkene.[6]

2-Propyl-2-heptenal is obtained from pentanal by aldol condensation, which is hydrogenated to the saturated branched 2-propylheptanol. This alcohol serves as a starting material for the PVC plasticizer di-2-propylheptyl phthalate (DPHP).

Pentanal (valeraldehyde) is oxidized to give valeric acid.[7]

References

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  1. ^ Merck Index, 11th Edition, 9813.
  2. ^ n-Valeraldehyde at chemicalland21.com
  3. ^ a b c d e NIOSH Pocket Guide to Chemical Hazards. "#0652". National Institute for Occupational Safety and Health (NIOSH).
  4. ^ "Valeraldehyde, 110-62-3".
  5. ^ Patent WO 2009/146985 der Evonik Oxeno GmbH.
  6. ^ Siegel, Hardo; Eggersdorfer, Manfred (2000). "Ketones". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a15_077. ISBN 9783527306732.
  7. ^ Riemenschneider, Wilhelm (2002). "Carboxylic Acids, Aliphatic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a05_235. ISBN 978-3527306732.