Description
1,2-Hexanediol is a linear aliphatic diol with a carbon chain length containing six carbons. It is a synthetic preservative and moisture-binding agent belonging to a class of agents known as higher molecular glycols. It is considered non-sensitizing. It is ideal for use as an emollient, humectant, and wetting agent in cosmetic and skin care products.
Chemical Properties
clear colorless to light yellow liquid.
Uses
DL-1,2-Hexanediol is a solvent used to dissolve other compounds in a formulation. It can be used in the ruthenium-catalyzed synthesis of oxazolidin-2-ones from urea. It can undergo ruthenium-hydride catalyzed dehydrative coupling with anilines to form substituted indole and quinoline products.
Application
In skin care: 1,2-Hexanediol is one of the most multi-functional ingredients in the cosmetic industry. It is used in skin care, hair care as well as beauty products. It is a great emollient as well as a humectant, that is, it preserves hydration on the skin while also softening it.
Preparation
1,2-Hexanediol was synthesized with an overall yield of approximately 45% using a multi-step process that involved a-bromination of caproic acid, followed by hydrolysis to a-hydroxycaproic acid, and concluded with reduction using lithium aluminum hydride. In an alternate method, the organic acid was oxidized with H2O2 to form a peroxy acid, which in turn epoxidized the olefin double bond and ultimately underwent hydrolysis to yield 1,2-hexanediol.
SYNTHESIS OF SOME HEXANEDIOLS
benefits
1,2 hexanediol is most commonly used as a solvent in skincare formulation. It pulls the moisture up from the deeper levels of the skin, as well as from the air, to help keep the top layers of your skin from drying out. This makes It very effective at keeping your skin hydrated and providing long-term moisture. It can also help to disperse pigments more evenly in makeup products and boost the antimicrobial activity of preservatives.
General Description
1,2-Hexanediol acts as cosurfactant, used for modifying the sodium dodecyl sulfate micelles. Solubility of 1,2-hexanediol in supercritical CO
2 has been reported. It has a tendency of self-association to form micelle-like aggregates.
Safety
1,2-Hexanediol is safe for skin and hair when used in lower concentrations. In an in-use safety evaluation for skin irritation and sensitization potential, 28 participants (males and females) were instructed to use a body wash containing 0.15% 1,2- hexanediol for a minimum of 3 times per week over a 30-day period. There was no evidence of erythema, edema, or dryness of application sites in any of the participants, and it was concluded that the product did not demonstrate a potential for eliciting skin irritation or sensitization.
Safety Assessment of 1,2-Glycols as Used in Cosmetics
Purification Methods
Fractionally distil it, preferably in a vacuum. Alternatively, dissolve it in Et2O, dry with K2CO3 then Na2SO4, filter, evaporate and distil it in a vacuum. The bis-4-nitrobenzoyl derivative has m 101.5-102.5o. [Rudloff Can J Chem 36 486 1958, Beilstein 1 I 251, 1 III 2200, 1 IV 2554.]
