Allyl alcohol

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Allyl alcohol
Names
IUPAC name
Prop-2-en-1-ol
Other names
1-Propen-3-ol
Allyl alcohol
Vinyl carbinol
Properties
C3H6O
CH2=CHCH2OH
Molar mass 58.08 g/mol
Appearance Colorless liquid
Odor Mustard-like
Density 0.854 g/cm3 (25 °C)
Melting point −129 °C (−200 °F; 144 K)
Boiling point 97 °C (207 °F; 370 K)
Misicible
Solubility Misicible with acetone, benzene, chloroform, diethyl ether, dichloromethane, isopropanol, DMSO, petroleum ether, toluene
Vapor pressure 23.8 mmHg (25 °C)
Acidity (pKa) 15.5 (H2O)
Thermochemistry
Hazards
Safety data sheet Sigma-Aldrich
Flash point 21 °C (70 °F; 294 K)
Lethal dose or concentration (LD, LC):
64 mg/kg (rat, oral)
Related compounds
Related compounds
Propanol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Allyl alcohol or prop-2-en-1-ol is an organic compound with the structural formula CH2=CHCH2OH. Allyl alcohol is the smallest representative of the allylic alcohols

Properties

Chemical

Epoxidation of allyl alcohol yields glycidol.

Allyl alcohol will isomerize into ketone by the action of the Grubbs reagent.

Strong oxidizers, like peroxides may cause polymerization of allyl alcohol.

Physical

Allyl alcohol is a colorless liquid, with a mustard-like odor. It is miscible with water and organic solvents.

Availability

Allyl alcohol is sold by lab suppliers, but it's difficult to acquire as it's quite toxic.

It is classified as an extremely hazardous substance in the United States as defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act (42 U.S.C. 11002), and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities.

Preparation

Allyl alcohol can be obtained by heating glycerol with oxalic acid at high temperatures (around 220-240 °C). Ammonium chloride may also be added as catalyst. The first product of this reaction is formic acid (this is a convenient route to obtain formic acid). After no more formic acid is produced, at temperatures between 220-225 °C, an equal amount of allyl alcohol and allyl formate distills over. The distillate was treated with sodium or potassium hydroxide to hydrolyze the formate and destroy any traces of acrolein produced, allowed to stand for 12h at room temp and finally distilled. The first distillate contains all the allyl alcohol, in the form of allyl alcohol/water azeotropic mixture (b.p. 87-88 °C) which may be dehydrated using anhydrous potassium carbonate to obtain anhydrous allyl alcohol.[1]

Alternatively, glycerol can be distilled with formic acid alone, and the purification process is similar to that above.[2][3]

Allyl alcohol can also be made by the rearrangement of propylene oxide, a reaction that is catalyzed by potassium alum at high temperature.

Projects

  • Make glycidol

Handling

Safety

Allyl alcohol is more toxic than related simple alcohols. Its threshold limit value (TLV) is 2 ppm. It is also a lachrymator.

When handling this compound, it's advised to use butyl rubber gloves, as they provide the best protection.

Storage

Allyl alcohol should be kept in airtight bottles, with a clear hazard label, in dark well ventilated places.

Disposal

Allyl alcohol should be diluted with a flammable solvent, like ethanol or acetone and burned in an incinerator, kiln, outside or in a special fumehood.

References

  1. https://www.erowid.org/archive/rhodium/chemistry/allylalcohol.html
  2. http://www.orgsyn.org/demo.aspx?prep=cv1p0042
  3. https://www.prepchem.com/synthesis-of-allyl-alcohol/

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