General Description
A light-yellow colored liquid. Slightly denser than water. Hence sinks in water. Boiling point 280°F. Flash point between 100 and 141°F. Used to make other chemicals.
Reactivity Profile
ACETYL METHYL CARBINOL(513-86-0) is a ketone and alcohol. 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. Flammable and/or toxic gases are generated by the combination of alcohols with alkali metals, nitrides, and strong reducing agents. They react with oxoacids and carboxylic acids to form esters plus water. Oxidizing agents convert them to aldehydes or ketones. Alcohols exhibit both weak acid and weak base behavior. They may initiate the polymerization of isocyanates and epoxides.
Air & Water Reactions
Flammable. Slightly soluble in water.
Health Hazard
Inhalation or contact with material may irritate or burn skin and eyes. Fire may produce irritating, corrosive and/or toxic gases. Vapors may cause dizziness or suffocation. Runoff from fire control may cause pollution.
Fire Hazard
HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion hazard indoors, outdoors or in sewers. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water.
Chemical Properties
Acetoin is a yellowish liquid with a bland, woody, yogurt odor and a fatty creamy “tub” butter taste. It is useful as a
flavor ingredient in butter, milk, yogurt or strawberry flavors.
Chemical Properties
clear yellow solution
Occurrence
Reported found in fresh apple, butter, cheddar cheese, coffee, cocoa, honey, wheat bread and wine
Definition
ChEBI: A methyl ketone that is butan-2-one substituted by a hydroxy group at position 3.
Aroma threshold values
Aroma characteristics at 1.0%: strong buttery and creamy
Taste threshold values
Taste characteristics at 10 ppm: sweet, creamy, dairy, and butter-like.
Synthesis
From diacetyl by partial reduction with zinc and acid. It is also a product of fermentation. Acetoin is an optically active
compound. The d(–)acetyl methyl carbinol is obtained from fermentation and, in mixture with other products, from the catalytic
oxidation of 2,3-butanediol. The 1(+)acetyl methyl carbinol is also obtained from fermentation. The optically pure form has not been
isolated; the optically inactive form is prepared synthetically
Purification Methods
Wash acetoin with EtOH until colourless, then with diethyl ether or acetone to remove biacetyl. Dry it in air by suction and dry further in a vacuum desiccator. [Beilstein 1 IV 3991.]
