Phenylacetaldehyde is an organic compound used in the synthesis of fragrances and polymers.[1] Phenylacetaldehyde is an aldehyde that consists of acetaldehyde bearing a phenyl substituent; the parent member of the phenylacetaldehyde class of compounds. It has a role as a human metabolite, a Saccharomyces cerevisiae metabolite, an Escherichia coli metabolite and a mouse metabolite. It is an alpha-CH2-containing aldehyde and a member of phenylacetaldehydes.[2]
| |
| Names | |
|---|---|
| Preferred IUPAC name
Phenylacetaldehyde | |
| Identifiers | |
3D model (JSmol)
|
|
| 385791 | |
| ChEBI | |
| ChemSpider | |
| ECHA InfoCard | 100.004.159 |
| EC Number |
|
| KEGG | |
PubChem CID
|
|
| UNII | |
CompTox Dashboard (EPA)
|
|
| |
| |
| Properties | |
| C8H8O | |
| Molar mass | 120.15 g/mol |
| Appearance | Colorless liquid |
| Density | 1.079 g/mL |
| Melting point | −10 °C (14 °F; 263 K) |
| Boiling point | 195 °C (383 °F; 468 K) |
| 2.210 g/L | |
| -72.01·10−6 cm3/mol | |
Refractive index (nD)
|
1.526 |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards
|
Harmful, Flammable |
| GHS labelling: | |
 
| |
| Danger | |
| H302, H314, H317 | |
| P260, P261, P264, P270, P272, P280, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P330, P333+P313, P363, P405, P501 | |
| Flash point | 87 °C (189 °F; 360 K) |
| Related compounds | |
Related 2-phenyl aldehydes
|
3,4-Dihydroxyphenylacetaldehyde |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
| |
Phenylacetaldehyde is one important oxidation-related aldehyde. Exposure to styrene gives phenylacetaldehyde as a secondary metabolite. Styrene has been implicated as reproductive toxicant, neurotoxicant, or carcinogen in vivo or in vitro. Phenylacetaldehyde could be formed by diverse thermal reactions during the cooking process together with C8 compounds is identified as a major aroma–active compound in cooked pine mushroom. Phenylacetaldehyde is readily oxidized to phenylacetic acid. Therefore will eventually be hydrolyzed and oxidized to yield phenylacetic acid that will be excreted primarily in the urine in conjugated form.[2]
Natural occurrence
editPhenylacetaldehyde occurs extensively in nature because it can be biosynthetically derived from the amino acid phenylalanine. Natural sources of the compound include chocolate,[3] buckwheat,[4] flowers, and communication pheromones from various insect orders.[5] It is notable for being a floral attractant for numerous species of Lepidoptera; for example, it is the strongest floral attractor for the cabbage looper moth.[6]
Uses
editFragrances and flavors
editThe aroma of pure substance can be described as honey-like, sweet, rose, green, grassy and is added to fragrances to impart hyacinth, narcissi, or rose nuances.[1] For similar reasons the compound can sometimes be found in flavored cigarettes and beverages.
Historically, before biotechnology approaches were developed, phenylacetaldehyde was also used to produce phenylalanine via the Strecker reaction as a step in the production of aspartame sweetener.[1]
Polymers
editPhenylacetaldehyde is used in the synthesis of polyesters where it serves as a rate-controlling additive during polymerization.[1]
Natural Medicine
editPhenylacetaldehyde is responsible for the antibiotic activity of maggot therapy.[7]
MAOI
editTheoretically, hydrazone formation and subsequent reduction of the phenylethylidenehydrazine gives phenelzine.[citation needed]
Preparation
editPhenylacetaldehyde can be obtained via various synthetic routes and precursors. Notable examples include:
- Isomerization of styrene oxide.[1]
- Dehydrogenation of 2-Phenylethanol over silver or gold catalysts.
- Darzens reaction between benzaldehyde and chloroacetate esters.
- Wacker oxidation of styrene.
- Hofmann rearrangement of Cinnamamide (aka (2E)-3-Phenylacrylamide).[8][9]
- Oxidation of Cyclooctatetraene with aqueous Mercury(II) sulfate.[10][11]
- Strecker degradation of phenylalanine.[12]
Reactivity
editPhenylacetaldehyde is often contaminated with polystyrene oxide polymer because of the especial lability of the benzylic alpha proton and the reactivity of the aldehyde. Aldol condensation of the initial dimer gives rise to a range of Michael acceptors and donors.
References
edit- ^ a b c d e Kohlpaintner, Christian; Schulte, Markus; Jürgen, Falbe; Lappe, Peter; Jürgen, Weber; Frey, Guido (2014). "Aldehydes, Araliphatic". Ullmann's Encyclopedia of Industrial Chemistry. 1. doi:10.1002/14356007.m01_m03.pub2. ISBN 9783527334773.
- ^ a b "Phenylacetaldehyde". pubchem.ncbi.nlm.nih.gov. National Library of Medicine. Retrieved 16 July 2020.
This article incorporates text from this source, which is in the public domain.
- ^ Schnermann, Petra; Schieberle, Peter (1997). "Evaluation of Key Odorants in Milk Chocolate and Cocoa Mass by Aroma Extract Dilution Analyses". Journal of Agricultural and Food Chemistry. 45 (3): 867–872. doi:10.1021/jf960670h.
- ^ Janes D, Kantar D, Kreft S, Prosen H (2009). "Identification of buckwheat (Fagopyrum esculentum Moench) aroma compounds with GC-MS". Food Chemistry. 112 (1): 120–124. doi:10.1016/j.foodchem.2008.05.048.
- ^ El-Sayed, Ashraf. "Semiochemical-2-phenylacetaldehyde". The Pherobase: Database of Insect Pheromones and Semiochemicals. Extensive Database of Insect Pheromones and Semiochemicals. Archived from the original on 30 June 2017. Retrieved 26 November 2014.
- ^ Heath, Robert R.; Landolt, Peter J.; Dueben, Barbara; Lenczewski, Barbara (1992-08-01). "Identification of Floral Compounds of Night-Blooming Jessamine Attractive to Cabbage Looper Moths". Environmental Entomology. 21 (4): 854–859. doi:10.1093/ee/21.4.854. ISSN 0046-225X.
- ^ Pavillard, E.R.; Wright, E. A. (1957). "An Antibiotic from Maggots". Nature. 180 (4592): 916–917. Bibcode:1957Natur.180..916P. doi:10.1038/180916b0. PMID 13483556. S2CID 4155906.
- ^ Weerman, R.A. (1913). "Einwirkung von Natriumhypochlorit auf Amide ungesättigter Säuren". Justus Liebigs Annalen der Chemie. 401 (1): 1–20. doi:10.1002/jlac.19134010102.
- ^ Adams, Rodger (1946). Organic Reactions Volume III. New York: John Wiley and Sons Inc. pp. 275, 276, & 285. ISBN 9780471005285.
- ^ Reppe, Walter; Schlichting, Otto; Klager, Karl; Toepel, Tim (1948). "Cyclisierende Polymerisation von Acetylen I Über Cyclooctatetraen". Justus Liebigs Annalen der Chemie. 560 (1): 1–92. doi:10.1002/jlac.19485600102.
- ^ Kunichika, Sango (1953). "Cyclopolyolefins Derived from Acetylene". Bulletin of the Institute for Chemical Research, Kyoto University. 31 (5): 323–335. hdl:2433/75368.
- ^ Schonberg, Alexander; Radwan, Moubacher (1952). "The Strecker Degradation of α-Amino Acids". Chemical Reviews. 52 (2): 261–277. doi:10.1021/cr60156a002.
