Musk ketone

Description

Musks are fragrant natural compounds produced by several animals and a few plant species. Animal gland–derived musks are so noticeable that many source animals have “musk” in their names: musk deer (Moschus?spp.}, muskrat (Ondatra zibethicus), musk ox (Ovibos moschatus), and several others.
But musk fragrance is so highly desired in perfumes and cosmetics that natural sources are insufficient to meet the demand—not to mention the desire to avoid sacrificing animals for the sake of perfume. Chemists have met this challenge by synthesizing a series of artificial musks, including helvetolide, a monocyclic musk; galaxolide, a polycyclic musk; muscone, a macrocyclic musk; and musk ketone (4-tert-butyl-2,6-dimethyl-3,5-dinitroacetophenone), an aromatic musk that is this week’s featured molecule.
Musk ketone dates to 1888, when German chemist Albert Baur made it serendipitously while he was trying to find a better way to produce the explosive TNT. In the perfume industry, musk ketone is called a fixative because it stabilizes the volatility and improves the tenacity of perfume aromas.
Concerns about fragrance ingredients entering the environment have prompted regulatory agencies to require cosmetics manufacturers to disclose the constituents of their products. Until now, these formulations have been closely guarded trade secrets. This year, in advance of specific directives, the consumer products giant Unilever said it would?voluntarily report such constituents, including musk ketone. The company said that ingredient lists will be available on its Web site sometime in 2018.

Chemical properties

White to light yellow crystal powde

Chemical properties

It forms yellowish crystals with a sweet, very persistent, slightly animal musk odor.Musk ketone is prepared by Friedel–Crafts acetylation of 1,3-dimethyl-5-tert-butylbenzene and nitration of the resulting 2,6- dimethyl-4-tert-butylacetophenone with nitric acid.
Musk ketone is widely used as a fixative in blossom and fantasy compositions.

Occurrence

Has apparently not been reported to occur in nature.

The Uses of Musk ketone

Musk ketone is used as fragrance and fixative in after-shave lotions, perfumes, ete.

Preparation

Nitration of the corresponding benzene derivative (Bedoukian, 1967).

Definition

ChEBI: 4'-tert-Butyl-2',6'-dimethyl-3',5'-dinitroacetophenone is an aromatic ketone.

General Description

Light yellow crystalline solid. Insoluble in water.

Air & Water Reactions

Insoluble in water.

Reactivity Profile

A nitrated ketone. Ketones are reactive with many acids and bases liberating heat and flammable gases (e.g., H2). The amount of heat may be sufficient to start a fire in the unreacted portion of the ketone. Ketones react with reducing agents such as hydrides, alkali metals, and nitrides to produce flammable gas (H2) and heat. Ketones are incompatible with isocyanates, aldehydes, cyanides, peroxides, and anhydrides. They react violently with aldehydes, HNO3, HNO3 + H2O2, and HClO4.

Fire Hazard

Flash point data is not available for Musk ketone, however, Musk ketone is probably combustible.

Flammability and Explosibility

Not classified

Purification Methods

Purify the ketone by recrystallisation from MeOH. It has a strong odour of musk and is used in perfumery. [Fuson et al. J Org Chem 12 587 1947, Beilstein 7 IV 808.]