Benzyl alcohol

Source: Wikipedia, the free encyclopedia.
Not to be confused with benzoic acid, cresol, or phenol.

Benzyl alcohol
Benzyl alcohol
Benzyl alcohol
Names
Preferred IUPAC name
Phenylmethanol
(Hydroxymethyl)benzene
Other names
Benzyl alcohol
α-Cresol
α-Toluenol
α-Hydroxytoluene
alpha-Hydroxyphenylmethane
Phenylcarbinol
Benzenemethanol
Benzyl hydroxide
Benzylic acid
Identifiers
3D model (
JSmol
)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard
 100.002.600 Edit this at Wikidata
EC Number
  • 202-859-9
E number E1519 (additional chemicals)
KEGG
RTECS number
  • DN3150000
UNII
  • InChI=1S/C7H8O/c8-6-7-4-2-1-3-5-7/h1-5,8H,6H2 checkY
    Key: WVDDGKGOMKODPV-UHFFFAOYSA-N checkY
  • InChI=1/C7H8O/c8-6-7-4-2-1-3-5-7/h1-5,8H,6H2
    Key: WVDDGKGOMKODPV-UHFFFAOYAH
  • c1ccc(cc1)CO
  • c1ccc(cc1)CO
Properties[1]
C7H8O
Molar mass 108.140 g·mol−1
Appearance Colorless liquid
Odor Slightly aromatic
Density 1.044 g/cm3
Melting point −15.2 °C (4.6 °F; 257.9 K)
Boiling point 205.3 °C (401.5 °F; 478.4 K)
3.50 g/100 mL (20 °C)
4.29 g/100 mL (25 °C)
Solubility in other solvents Soluble[vague] in benzene, methanol, chloroform, ethanol, ether, acetone
log P 1.10
Vapor pressure 0.18 kPa (60 °C)
Acidity (pKa) 15.40
−71.83·10−6 cm3/mol
1.5396
Viscosity 5.474 cP
1.67 D
Thermochemistry
217.8 J/(K·mol)
Std enthalpy of
formation
(ΔfH⦵298)
 −352 kJ/mol
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
1
0
Flash point 93 °C (199 °F; 366 K)
436 °C (817 °F; 709 K)
Explosive limits
 1.3–13%
Lethal dose or concentration (LD, LC):
1250 mg/kg (rat, oral)
Safety data sheet (SDS) External MSDS
Pharmacology
P03AX06 (WHO)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Benzyl alcohol (also known as α-

anion produced by deprotonation
of the alcohol group is known as benzylate or benzyloxide.

Natural occurrences

Benzyl alcohol is produced naturally by many plants and is commonly found in fruits and teas. It is also found in a variety of

castor sacs of beavers.[3] Benzyl esters also occur naturally.[4]

Preparation

Benzyl alcohol is produced industrially from toluene via benzyl chloride, which is hydrolyzed:

C6H5CH2Cl + H2O → C6H5CH2OH + HCl

Another route entails hydrogenation of benzaldehyde, a by-product of the oxidation of toluene to benzoic acid.[5]

For laboratory use, Grignard reaction of phenylmagnesium bromide (C6H5MgBr) with formaldehyde and the Cannizzaro reaction of benzaldehyde also give benzyl alcohol. The latter also gives benzoic acid, an example of an organic disproportionation reaction.

Reactions

Like most alcohols, it reacts with carboxylic acids to form esters. In organic synthesis, benzyl esters are popular protecting groups because they can be removed by mild hydrogenolysis.[6]

Benzyl alcohol reacts with acrylonitrile to give N-benzylacrylamide. This is an example of a Ritter reaction:[7]

C6H5CH2OH + NCCHCH2 → C6H5CH2N(H)C(O)CHCH2

Applications

Benzyl alcohol is used as a general

epoxy resin coatings. Thus it can be used in paint strippers, especially when combined with compatible viscosity enhancers to encourage the mixture to cling to painted surfaces.[8]

It is a precursor to a variety of

flavor industries. E.g. benzyl benzoate, benzyl salicylate, benzyl cinnamate, dibenzyl ether, benzyl butyl phthalate
.

It can be used as a local anesthetic, especially with epinephrine.[9]

As a dye solvent, it enhances the process of dying wool, nylon, and leather.[10]

Use in health care

Benzyl alcohol is used as a

bacteriostatic preservative at low concentration in intravenous medications, cosmetics, and topical drugs.[11] Some caution is necessary if a high percent of benzyl alcohol is used as benzaldehyde arises from benzyl alcohol when used as preservative in an injectable formulation solution.[11][12]

Benzyl alcohol, sold under the brand name Ulesfia, was approved by the U.S.

asphyxiation.[13]

Benzyl alcohol is used effectively for treating lice infestations as the active ingredient in lotion shampoo with 5% benzyl alcohol.[13]

Benzyl alcohol is an ingredient used in the manufacture of soaps, topical creams, skin lotions, shampoos, and facial cleansers and is popular due to its anti-bacterial and anti-fungal properties. It is a common ingredient in a variety of household products.

Safety

Sensitization to benzyl alcohol occurs very rarely, mainly in patients with stasis dermatitis.[14]

Benzyl alcohol is not considered to be a carcinogen, and no data are available regarding teratogenic or reproductive effects.[5]

Benzyl alcohol has low acute toxicity with an LD50 of 1.2 g/kg in rats.[5] It oxidizes rapidly in healthy individuals to benzoic acid, conjugated with glycine in the liver, and excreted as hippuric acid. Very high concentrations can result in toxic effects including respiratory failure, vasodilation, hypotension, convulsions, and paralysis.

Benzyl alcohol is toxic to neonates and is associated with the gasping syndrome.[15][16]

References

  1. ^ "Benzyl alcohol". Archived from the original on 26 July 2009.
  2. ISBN 091191028X
    , 1138
  3. ISBN 978-0-8014-5010-5
    .
  4. PMID 12226525
    .
  5. ^
    ISBN 978-3527306732
    .
  6. ^ Furuta, Kyoji; Gao, Qing-Zhi; Yamamoto, Hisashi (1995). "Chiral (Acyloxy)borane Complex-Catalyzed Asymmetric Diels-Alder Reaction: (1R)-1,3,4-Trimethyl-3-Cyclohexene-1-Carboxaldehyde". Organic Syntheses. 72: 86; Collected Volumes, vol. 9, p. 722.
  7. ^ Parris, Chester L. (1962). "N-benzylacrylamide". Organic Syntheses. 42: 16; Collected Volumes, vol. 5, p. 73.
  8. ^ Benzyl alcohol, chemicalland21.com, archived from the original on 21 April 2009, retrieved 14 May 2006
  9. PMID 10216324
    .
  10. ISBN 978-1-890595-66-1
    .
  11. ^
    PMID 21828928
    .
  12. PMID 16564153
    .
  13. ^ a b c d "Ulesfia- benzyl alcohol lotion". DailyMed. 8 April 2019. Retrieved 27 April 2020.
  14. ^ "Registration Dossier - ECHA". echa.europa.eu. Retrieved 20 April 2023.
  15. ^ Carl R. Baum (2008), "Examples of mass exposures involving the pediatric population", in Jerrold B. Leikin; Frank P. Paloucek (eds.), Poisoning and Toxicology Handbook (4th ed.), Informa, p. 726.
  16. PMID 7133084
    .

External links
Retrieved from "https://en.wikipedia.org/w/index.php?title=Benzyl_alcohol&oldid=1213537316"