Feniletil-alkohol
Phenylethyl alcohol, or 2-phenylethanol, is an organic compound with the chemical formula C₈H₁₀O. It is a colorless liquid with a pleasant floral odor.
- Type
- Sirovina
- Olfactive family
- Cvetni
- Source
- Mainly chemical synthesis; also extracted from rose petals
- Chemical class
- alcohol
Miris
Detaljno
Zanimljivosti
The pure compound is difficult to crystallize because it tends to supercool to a glass. Natural 2-phenylethanol can cost 250 to 300 times more than the chemically synthesized compound. The compound also forms a number of azeotropes.
Dobijanje i hemija
Način dobijanja
About 93% of the commercialized compound is obtained by chemical synthesis. The most common commercial route is the Friedel-Crafts reaction between benzene and ethylene oxide in the presence of aluminium trichloride. This alkylation of benzene with ethylene oxide takes place at temperatures lower than 25 °C. Hydrogenation of styrene oxide over Raney nickel also gives phenylethyl alcohol. In a Grignard route, chlorobenzene is converted to phenylmagnesium chloride, which reacts with ethylene oxide at 100 °C. It can also be made by reducing phenylacetic acid with sodium borohydride and iodine in THF. Natural 2-phenylethanol is extracted mainly from rose petals. For rose flavor, the petals are usually harvested by hand and distilled in the presence of water, which gives an aqueous phase and a lipophilic phase. The aqueous phase is the rose water, in which 2-phenylethanol is the main component, while the lipophilic phase is the essential oil, which also contains it. It can also be produced by biotransformation of L-phenylalanine into 2-phenylethanol via the Ehrlich pathway, a process observed in yeasts and bacteria. Phenylethyl alcohol can also be produced by biotransformation of L-phenylalanine using immobilized yeast Saccharomyces cerevisiae. Product made by this biotransformation can be considered natural. Biotechnological production is not yet attractive for industrial applications because of low titer and high production costs compared with the synthetic route.
- Formula
- C₈H₁₀O
- CAS
- 60-12-8
- Izgled
- Colorless, viscous liquid
- Jačina mirisa
- Extremely mild
- Sinonimi
- 2-Phenylethanol, Phenethyl alcohol, Phenethanol, Benzyl carbinol, β-Hydroxyethylbenzene, Benzeneethanol, PEA
No IFRA Standard for the material itself (51st Amendment)
- Tačka ključanja
- 219–221 °C @ 760 mm Hg
- Tačka topljenja
- -27 °C
- Tačka paljenja
- 96 °C (205 °F), closed cup
- Relativna gustina
- 1.017 to 1.019
- Indeks prelamanja
- 1.5325 @ 20 °C
U parfemima
Phenylethyl alcohol is a common ingredient in flavors and perfumery, particularly when the odor of rose is desired. It is a flavor compound with a rose-like scent, used in the cosmetics, perfume, home care and food industries. It is also used in the preparation of artificial volatile oils. Its use in perfumery is especially in rose perfumes. Its rose-like odor and antibacterial properties make it a high-value compound for the cosmetic, food and flavor industries.
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