Product name: DL-Limonene
CAS: 138-86-3
Molecular formula: C10H16
EINECS: 205-341-0
Limonene Properties
| Melting point | -84--104 °C |
| Boiling Point | 170-180 °C (lit.) |
| Density | 0.86 g/mL at 20 °C (lit.) |
| Vapor density | 4.7 (vs air) |
| Vapor pressure | <3 mm Hg ( 14.4 °C) |
| Refractive Index | n20/D 1.473(lit.) |
| Flash point | 119 °F |
| Storage conditions | Store below +30°C. |
| Solubility | Chloroform: slightly soluble |
| Form | liquid |
| Color | Transparent colorless to light yellow |
| Odor | Pleasant, pine-lemony scent |
Chemical properties
Dipentene is a colorless, flammable liquid at room temperature with a pleasant lemon scent. It is insoluble in water and miscible with ethanol.
Essential oil ingredients
Limonene, also known as limonene, is the main component of the essential oil extracted from citrus peel of the Rutaceae family, but it is not the main flavor of citrus aroma. Limonene has three isomers. Natural limonene is optically active, namely levo-limonene and dextro-limonene, while synthetic limonene is not optically active and is racemic limonene. The more common ones in aromatic organic chemistry are levo-limonene and dextro-limonene. Dextro-limonene is mainly found in lemon oil, tangerine oil, orange oil and other plant essential oils, and has a sweet taste; levo-limonene is mainly found in peppermint oil and pine needle oil, and has a fresh smell.
Uses
Used as a raw material for synthetic rubber and fragrances, and also as a solvent
The right-handed isomer is often used. It can be used as a raw material for preparing artificial orange blossom, sweet flower, lemon, and bergamot oil. It can also be used as a fresh top note fragrance for cosmetics, soaps, and daily chemical fragrances. It is suitable for cologne type, jasmine type, lavender type in floral fragrance, and pine, aldehyde, woody, fruity, or fresh fragrance types. It is used as a modifier in edible flavors in white lemon, fruity, and spicy formulas.
Dipentene can be used as enamel, lacquer and various oil-containing resins, resin wax, metal driers and solvents; used to make synthetic resins and synthetic rubbers; used to blend orange blossom essence, citrus oil essence, etc.; it can also be made into a substitute for lemon essential oil. Limonene is directional oxidized to produce carvone; in the presence of inorganic acid, limonene reacts with water to produce α-terpineol and hydrated terpene diol; under the action of platinum or color catalysts, it is hydrogenated to produce para-alkane, and dehydrogenated to produce para-cymene. It is also used as oil dispersant, rubber additive, wetting agent, etc.
Used as a solvent, also used in fragrance synthesis and pesticide production
Production method
Dipentene is widely present in natural plant essential oils. Among them, the main ones containing right-handed isomers are tangerine oil, lemon oil, orange oil, camphor white oil, etc. The ones containing left-handed isomers are peppermint oil, etc. The ones containing racemic isomers are orange blossom oil, fir oil and camphor white oil, etc. When manufacturing this product, it is fractionated and prepared from the above essential oils respectively. It can also be extracted from terpenes in general essential oils, or it can be obtained as a by-product in the process of processing camphor oil and synthesizing camphor. The obtained dipentene can be purified by distillation to obtain limonene. Using turpentine oil as raw material, fractionate and cut α-pinene, isomerize to produce camphene, and then fractionate to obtain it. The by-product of camphene is dipentene. In addition, dipentene can also be produced as a by-product when turpentine oil is hydrated to produce terpineol.
