Chinese Name: L- menthol
English Name: L-Menthol
The alias name: L- menthol natural menthol menthol (left)
More: alcohol Natural menthol Menthol alias L-Meng (L)
The molecular formula: C10H20O
Molecular weight: 156.27
CAS number: 2216-51-5
MDL number: MFCD00062979
EINECS number: 218-690-9
RTECS number: OT0700000
BRN number: 1902293
PubChem number: 24882791
Characters: white needle crystal with cool mint aromas.
Density (g/mL, 20oC): 0.89
The melting point (oC): 43-45
Boiling point (oC, atmospheric pressure): 103-104
The refractive index (nD20): 1.46
Flash point (oF): 200
Specific rotation (589nm, c=10, EtOH): -51 o
Point of ignition or ignition temperature (oC): 91
Solubility: soluble in alcohol; chloroform; ether; acetic acid; liquid paraffin and petroleum ether, slightly soluble in water
Synthesis method:
Menthol mint oil purification from natural or synthetic method. Mint Labiatae plant aboveground part (stems; branches; leaves and inflorescence) obtained by steam distillation from the essential
oils known crude mint oil, oil production rate is 0.5-0.6.
There are several methods of synthesis of thin and brain.
1 from citronellal manufacturing easy ring into different properties of isopulegol by citronellal, citronellal to dextral using an acid catalyst (such as silica gel) cyclizes sinistral isopulegol,
separate the left-hand isopulegol, hydrogenation of l-menthol. The three-dimensional structure by thermal cracking of tutor can partially was transformed into dextral citronellal, recycling
use.
2 from the thymol in manufacturing presence in m-cresol aluminum, m-cresol was on the alkylation reaction of thymol. By catalytic hydrogenation of all four stereoisomers of menthol (i.e. racemic
menthol; racemic new menthol; racemic isomenthol and racemic neoisomenthol). The distillation, cancel the rotary menthol ester fraction, manufacturing after repeated re crystallization, separation
and optical resolution of isomers. L menthol ester is separated, by saponification after menthol.
Use:
Menthol and racemic menthol can all be used as a toothpaste; perfume; aromatizing agent drinks and candy etc.. Used as a stimulant drug in medicine, applied to the skin or mucous membrane, have
cool and refreshing and antipruritic effect; oral administration can be used as a carminative, used for headache and nasal; pharynx; laryngitis etc.. The ester used in perfumes and drugs.
