Heptanal
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| Preferred IUPAC name
Heptanal | |
| Other names
Heptanaldehyde
Aldehyde C-7 Enanthaldehyde Heptyl aldehyde n-Heptanal | |
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| ECHA InfoCard | 100.003.545 Edit this at Wikidata |
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PubChem CID
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CompTox Dashboard (EPA)
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| Properties | |
| C7H14O | |
| Molar mass | 114.18 |
| Appearance | Clear 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
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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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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]
Production
[edit ]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]
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
[edit ]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
[edit ]Heptanal can be used for the production of 1-heptanol via hydrogenation:
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]
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]
Full hydrogenation provides the branched primary alcohol 2-pentylnonan-1-ol, also accessible from the Guerbet reaction from heptanol.[15]
References
[edit ]- ^ Merck Index, 11th Edition, 4578.
- ^ a b c 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) - ^ F. Krafft, Distillation of castor oil, under educed pressure, Analyst, 3, 329a (1878).
- ^ A. Chauvel, G. Lefebvre, Petrochemical Processes: Technical and Economic Characteristics, vol. 2, p. 277, Editions Technip, Paris, 1989, ISBN 2-7108-0563-4.
- ^ A. Fischbach et al on behalf of Oxea Deutschland GmbH (20 May 2009). Verfahren zur Herstellung von Aldehyden, German patent DE 102007053385.
- ^ a b G. A. Burdock, Fenaroli’s Handbook of Flavor Ingredients, Fifth Edition, 2005, CRC Press, Boca Raton, Fl., ISBN 0-8493-3034-3.
- ^ "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.
- ^ a b c d Record in the GESTIS Substance Database of the Institute for Occupational Safety and Health
- ^ Acros Organics (rev. 19 Nov 2012). Heptaldehyde, stabilized (safety data sheet).
- ^ 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.
- ^ 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.
- ^ alpha-Amylzimtaldehyd (rev. 4 Aug 2000) at the Riechstofflexikon [Odorant Dictionary], vol. A.
- ^ J. M. Hornback, Organic Chemistry, 2nd edition, p. 886, Thomson Brooks/Cole, 2006, ISBN 0-534-49317-3.
- ^ 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.
- ^ G.H. Knothe: Lipid Chemistry, Guerbet Compounds Archived 2016年05月21日 at the Wayback Machine, AOCS Lipid Library, 22 December 2011.