Heptanal

Last updated
Heptanal [1]
Heptanal.png
Names
Preferred IUPAC name
Heptanal
Other names
Heptanaldehyde
Aldehyde C-7
Enanthaldehyde
Heptyl aldehyde
n-Heptanal
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.003.545 OOjs UI icon edit-ltr-progressive.svg
KEGG
PubChem CID
UNII
  • InChI=1S/C7H14O/c1-2-3-4-5-6-7-8/h7H,2-6H2,1H3 Yes check.svgY
    Key: FXHGMKSSBGDXIY-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/C7H14O/c1-2-3-4-5-6-7-8/h7H,2-6H2,1H3
    Key: FXHGMKSSBGDXIY-UHFFFAOYAJ
  • O=CCCCCCC
Properties
C7H14O
Molar mass 114.18
AppearanceClear liquid
Density 0.80902 at 30 °C
Melting point −43.3 °C (−45.9 °F; 229.8 K)
Boiling point 152.8 °C (307.0 °F; 425.9 K)
Slightly soluble
-81.02·10−6 cm3/mol
Related compounds
Related aldehydes
 Hexanal

Octanal

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Heptanal or heptanaldehyde is an alkyl aldehyde. It is a colourless liquid with a strong fruity odor, which is used as precursor to components in perfumes and lubricants. [2]

Contents

Production

The formation of heptanal in the fractional distillation of castor oil [3] was already described in 1878. The large-scale production is based on the pyrolytic cleavage of ricinoleic acid [4] (Arkema method) and on the hydroformylation of 1-hexene with rhodium 2-ethylhexanoate as a catalyst upon addition of some 2-ethylhexanoic acid (Oxea method): [2] [5]

Hydroformylierung von 1-Hexen IS.svg

Heptanal naturally occurs in the essential oils of ylang-ylang ( Cananga odorata ), clary sage ( Salvia sclarea ), lemon ( Citrus x limon ), bitter orange ( Citrus x aurantium ), rose (Rosa) and hyacinth (Hyacinthus). [6]

Properties

Heptanal is a flammable, slightly volatile colorless liquid of pervasive fruity to oily-greasy odor, [7] which is miscible with alcohols [6] and practically insoluble in water. [8] Because of its sensitivity to oxidation, heptanal is filled under nitrogen and stabilized with 100 ppm hydroquinone. [9]

Heptanal forms flammable vapor-air mixtures. The compound has a flash point of 39.5 °C. [8] The explosion range is between 1.1% by volume as the lower explosion limit (LEL) and 5.2% by volume as the upper explosion limit. [8] Its ignition temperature is 205 °C. [8]

Uses

Heptanal can be used for the production of 1-heptanol via hydrogenation:

Heptanol-Synthese.svg

The oxidation of heptanal with oxygen in the presence of a rhodium catalysts leads at 50 °C to heptanoic acid in 95% yield. [10] Heptanal reacts with benzaldehyde in a Knoevenagel reaction under basic catalysis with high yield and selectivity (> 90%) to jasminaldehyde, [11] [2] which is mostly used in fragrances for its jasmine-like aroma as a cis/trans isomer mixture. [12]

Jasminaldehyd 2 IS.svg

A by-product of the given reaction is the unpleasant rancid smelling (Z)-2-pentyl-2-nonenal. [13] Nevertheless, heptanal can be converted into (Z)-2-pentyl-2-nonenal virtually quantitatively in the presence of aqueous boric acid upon azeotropic removal of water. [14]

2-Pentyl-2-nonenal IS.svg

Full hydrogenation provides the branched primary alcohol 2-pentylnonan-1-ol, also accessible from the Guerbet reaction from heptanol. [15]

References

  1. ↑ Merck Index, 11th Edition, 4578.
  2. 1 2 3 Christian Kohlpaintner, Markus Schulte, Jürgen Falbe, Peter Lappe, Jürgen Weber. "Aldehydes, Aliphatic". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi:10.1002/14356007.a01_321.pub2. ISBN   978-3-527-30673-2.{{cite encyclopedia}}: CS1 maint: multiple names: authors list (link)
  3. ↑ F. Krafft, Distillation of castor oil, under educed pressure, Analyst, 3, 329a (1878).
  4. ↑ A. Chauvel, G. Lefebvre, Petrochemical Processes: Technical and Economic Characteristics, vol. 2, p. 277, Editions Technip, Paris, 1989, ISBN   2-7108-0563-4.
  5. ↑ A. Fischbach et al on behalf of Oxea Deutschland GmbH (20 May 2009). Verfahren zur Herstellung von Aldehyden, German patent DE 102007053385.
  6. 1 2 G. A. Burdock, Fenaroli’s Handbook of Flavor Ingredients, Fifth Edition, 2005, CRC Press, Boca Raton, Fl., ISBN   0-8493-3034-3.
  7. ↑ "Richtwerte für gesättigte azyklische aliphatische C4- bis C11-Aldehyde in der Innenraumluft" (PDF). Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz. 52 (6): 650–659. 27 June 2009. doi:10.1007/s00103-009-0860-2. PMID   19557457.
  8. 1 2 3 4 Record in the GESTIS Substance Database of the Institute for Occupational Safety and Health
  9. ↑ Acros Organics (rev. 19 Nov 2012). Heptaldehyde, stabilized (safety data sheet).
  10. ↑ H. Springer and P. Lappe, on behalf of Celanese Chem Europe GmbH (3 May 2001). Verfahren zur Herstellung aliphatischer Carbonsäuren aus Aldehyden, German patent DE 10010771.
  11. ↑ Pérez-Sánchez, María; de María, Pablo Domínguez (2013). "Synthesis of natural fragrance jasminaldehyde using silica-immobilized piperazine as organocatalyst". Catalysis Science & Technology. 3 (10): 2732. doi:10.1039/C3CY00313B.
  12. ↑ alpha-Amylzimtaldehyd (rev. 4 Aug 2000) at the Riechstofflexikon [Odorant Dictionary], vol. A.
  13. ↑ J. M. Hornback, Organic Chemistry, 2nd edition, p. 886, Thomson Brooks/Cole, 2006, ISBN   0-534-49317-3.
  14. ↑ Offenhauer, Robert D.; Nelsen, Stephen F. (February 1968). "Aldehyde and ketone condensation reactions catalyzed by boric acid". The Journal of Organic Chemistry. 33 (2): 775–777. doi:10.1021/jo01266a059.
  15. ↑ G.H. Knothe: Lipid Chemistry, Guerbet Compounds Archived 2016-05-21 at the Wayback Machine , AOCS Lipid Library, 22 December 2011.
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