Phenethyl alcohol

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Phenethyl alcohol
Phenethyl alcohol bottle sample.jpg
Phenethyl alcohol bottle and sample.
Names
IUPAC name
2-Phenylethanol
Preferred IUPAC name
2-Phenylethan-1-ol
Other names
2-Phenylethanol
Benzeneethanol
Benzyl carbinol
PEA
Phenethyl alcohol
Phenyl-2-ethanol
β-Hydroxyethylbenzene
Properties
C8H10O
C6H5CH2CH2OH
Molar mass 122.16 g/mol
Appearance Colorless viscous liquid
Odor Soft, floral
Density 1.017 g/cm3 (20 °C)
Melting point −27 °C (−17 °F; 246 K)
Boiling point 218.2 °C (424.8 °F; 491.3 K)
2.22 g/100 ml (25 °C)
Solubility Miscible with acetone, alcohols, chloroform, glycerol, propylene glycol
Slightly soluble in mineral oil
Vapor pressure 0.09 mmHg (25 °C)
Hazards
Safety data sheet Sigma-Aldrich
Flash point 102 °C (215.6 °F; 305 K)
Related compounds
Related compounds
Benzyl alcohol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Phenethyl alcohol or 2-phenylethanol, is an organic compound with the formula C8H10O.

Properties

Chemical

Oxidation of phenethyl alcohol yields phenylacetic acid.

Physical

Phenethyl alcohol is a colorless liquid, immiscible with water, but miscible with many organic solvents. Its odor has been described as "floral" or "rose-like", though some claim it smells closer to crushed plant seeds, while having a honey-like scent at high concentration. This may also depend on the purity of the reagent.

Availability

Phenethyl alcohol is sold by chemical suppliers.

It occurs widely in nature, being found in a variety of essential oils.

Preparation

Phenethyl alcohol can also be prepared by the Grignard reaction between phenylmagnesium bromide and ethylene oxide:

C6H5MgBr + CH2CH2O → C6H5CH2CH2OMgBr
C6H5CH2CH2OMgBr + H+ → C6H5CH2CH2OH

Industrially 2-phenylethanol is prepared via the Friedel-Crafts reaction between benzene and ethylene oxide in the presence of anhydrous aluminium chloride.

C6H6 + CH2CH2O + AlCl3 → C6H5CH2CH2OAlCl2 + HCl

The reaction affords the aluminium alkoxide that is subsequently hydrolyzed to the desired product.

C6H5CH2CH2OAlCl2 + H2O → C6H5CH2CH2OH + AlCl2(OH)

It is also possible to produce phenethyl alcohol by the reduction of phenylacetic acid using sodium borohydride and iodine in THF.[1]

Projects

  • Make perfumes
  • Make phenethyl esters
  • Make phenylacetic acid

Handling

Safety

Phenethyl alcohol has low toxicity and it's a safe component of perfumes and aromas.

Storage

Phenyl ethanol should be kept in dark amber glass bottles. Prolonged contact with air will cause it to turn slightly yellowish, but this usually does not affect its purity.

Disposal

No special disposal is required.

References

  1. Kanth JV, Periasamy M (1991). "Selective Reduction of Carboxylic Acids into Alcohols Using NaBH and I2". Journal of Organic Chemistry. 56: 5964–5965

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