| Allyl- is the
prefix for the univalent organic group, -CH2=CHCH2. Allyl alcohol is
an example, CH2=CHCH2OH, clear, pungent liquid, boiling at 96 C; soluble in
water. It is prepared from allyl chloride by hydrolysis. Allyl compound,
an alkene hydrocarbon, has a vinyl group, CH2=CH-, attached to a methylene -CH2.
Because of the highly reactive solid bond, allyl can undergo free radical addition to solid bond which
readily combine with themselves or other monomers to form homopolymers or co-polymers
which are used in the production of coatings, adhesives and elastomers. In addition
to free radical addition,
allyl compounds can participate in a wide variety of reactions
including electrophilic additions, allylic substitution
and oxidation. Allyl,
an unsaturated bond, imparts a characteristic
odor in some compounds. An example is allyl
isothiocyanate which is the main ingredient of black mustards.
(white mustard consists principally of
p-hydroxybenzyl isothiocyanate). Allyl
isothiocyanate is called mustard oil.
Allyl esters are involved in fragrance, flavor, or odor.
Allyl chloride is a
compound derived by the chlorination of propylene. Allyl chloride is toxic and
affects the lungs, kidneys, and liver by ingestion and inhalation. It can be
absorbed into the body by inhalation and through the skin. It is very reactive
compound. It reacts violently with strong oxidants and metals such as aluminum,
magnesium, zinc, and thus cause fire and explosion hazard. Allyl chloride is a
versatile intermediate. It has dual reactive functions of the solid bond and the
chlorine atom in the short chain ( C 3). Allyl chloride consumption is linked
primarily to the production of quaternary ammonium
salts for water
treatment. It is used to prepare epichlorohydrin as well as glycidyl ether
derivatives, which are used in epoxy resin production and its diluents. It is
used in the preparation of other allyl compounds including allyl sulfonates
and allyl amines for the
target compound production such as ion exchange resins, thermosetting resins,
eugenol and pharmaceuticals and insecticides. It is also used in the preparation of
fragrance and flavor chemicals. An example is the synthetic mustard oil, allyl
isothiocyanate which is used as a fumigant, counterirritant in ointments and
plasters.
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