Chemical Property of MENTHOL
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Chemical Property:
- Vapor Pressure:0.8 mm Hg ( 20 °C)
- Melting Point:34-36 °C(lit.)
- Refractive Index:1.4615
- Boiling Point:216 °C(lit.)
- Flash Point:200 °F
- PSA：20.23000
- Density:0.89 g/mL at 25 °C(lit.)
- LogP:2.43950
- Storage Temp.:2-8°C
- Solubility.:Practically insoluble in water, very soluble in ethanol (96 per cent) and in light petroleum, freely soluble in fatty oils and in liquid paraffin, very slightly soluble in glycerol.
- Purity/Quality:
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99% *data from raw suppliers
D,L-Menthol solution certified reference material, 2000?μg/mL in methanol, ampule of 1?mL *data from reagent suppliers
Safty Information:
- Pictogram(s):
R37/38:;
R41:;
- Hazard Codes:Xn,Xi
- Statements:
37/38-41-48/20/22-40-38-22
- Safety Statements:
36/37/39-36-26
- MSDS Files:
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SDS file from LookChem
Useful:
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Physical properties
Physical Properties. The eight optically active menthols differ in their sensory
properties. (?)-Menthol has a characteristic peppermint odor and also
exerts a cooling effect. The other isomers do not possess this cooling effect and
are, therefore, not considered to be “refreshing.” Racemic menthol occupies an
intermediate position; the cooling effect of the (?)-menthol present is distinctly
perceptible.
The enantiomeric menthols have identical physical properties (apart from their
specific rotations), but the racemates differ from the optically active forms in, for
example, theirmelting points.Although the differences between the boiling points
are small, the (racemic) stereoisomers can be separated by fractional distillation.
Boiling points (in °C at 101.3 kPa) are as follows:
rac-neomenthol, 211.7
rac-neoisomenthol 214.6
rac-menthol, 216.5
rac-isomenthol, 218.6
Other physical constants of commercially available levorotatory and racemic
menthols are as follows: (?)-menthol, mp 43 °C, [α]20
D ?50° (ethanol, 10%);
racemic menthol, mp 38 °C.
Chemical Properties. Hydrogenation of menthols yields p-menthane; oxidation
with chromic acid or catalytic dehydrogenation yields menthones. Dehydration
under mild conditions yields 3-p-menthene as the main product. Reaction with
carboxylic acids or their derivatives yields menthyl esters, which are used mainly
as aroma substances and in pharmaceutical preparations and formulations. The
esterification of menthols with benzoic acid is used on an industrial scale in the
resolution of racemic menthol.
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Indications
Menthol, a cyclic alcohol (derived from peppermint, other mint oils, or prepared
synthetically), relieves itching by generating a cool sensation. It is usually used in
0.25% to 2% concentrations but is present in concentrations as high as 16% in
some OTC products.
