Acetylacetone

Description

Acetylacetone (2,4-pentanedione) is a clear or slightly yellowish liquid with a putrid odour. It is readily soluble in water and in organic solvents and incompatible with light, ignition sources, excess heat, oxidising agents, strong reducing agents, and strong bases. On decomposition, acetylacetone releases hazardous products such as carbon monoxide, irritating and toxic fumes and gases, and carbon dioxide. Acetylacetone is used in the production of anti-corrosion agents and its peroxide compounds for the radical initiator application for polymerisation. It is used as a chemical intermediate for drugs (such as sulphamethazine, nicarbazine, vitamin B6, and vitamin K) and pesticides sulfonylurea herbicides and pesticides. It is used as an indicator for the complexometric titration of Fe (III), for the modification of guanidino groups and amino groups in proteins, and for the preparation of metal acetylacetonates for catalyst application.

Chemical properties

clear liquid

Chemical properties

Acetylacetone (2,4-pentanedione) is a clear or slightly yellowish liquid with a putrid odor. It is readily soluble in water. It is with other incompatible materials, light, ignition sources, excess heat, oxidizing agents, strong reducing agents, and strong bases. On decomposition, acetylacetone releases hazardous products, such as carbon monoxide, irritating and toxic fumes and gases, and carbon dioxide. Acetylacetone is used in the production of anticorrosion agents and its peroxide compounds for the radical initiator application for polymerization. It is used as a chemical intermediate for drugs (such as sulfamethazine, nicarbazine, vitamin B6, and vitamin K), sulfonylurea herbicides, and pesticides. It is used as a solvent for cellulose acetate, as an additive in gasoline and lubricant, as a dryer of paint and varnish. It is used as an indicator for the complexometric titration of Fe(III), for the modifi cation of guanidino groups and amino groups in proteins, and in the preparation of metal acetylacetonates for catalyst application.

Chemical properties

2,4-Pentanedione is a colorless to yellowish liquid with a sour, rancid odor. The Odor Threshold is 0.01 ppm. Or Ethereal-minty odor, somewhat metallic or "chemical". In high dilution, the flavor in aqueous medium is sweet, remotely reminiscent of Peppermint sweetness. Not very stable. The enol form readily passes into equilibrium mixture. Prod. from Acetone plus Ethyl acetate, or Acetone plus Acetic anhydride (with Boron trifluoride).

Chemical properties

Acetylacetone is a beta-diketone that is pentane in which the hydrogens at positions 2 and 4 are replaced by oxo groups. It is a conjugate acid of an acetylacetonate. Pentane-2,4-dione appears as a colorless or yellow colored liquid. Less dense than water. Vapors are heavier than air. Used as a solvent in paints and varnishes.

The Uses of Acetylacetone

Acetylacetone was used in preparing Y₂0₃, La₂0₃ and La₂CuO₄ thin films and the titanate/anatase dual-phase photocatalyst.

The Uses of Acetylacetone

Forms organometallic complexes which are used as gasoline additives, lubricant additives, driers for varnishes and printer's inks, fungicides, insecticides, colors.

The Uses of Acetylacetone

Acetyl acetone is used as a reagent fororganic synthesis and as a transition metalchelating agent. Its organometallic complexes are used as additives for gasoline andlubricants, and in varnishes, color, ink, andfungicides.

The Uses of Acetylacetone

Chemical intermediate, metal chelator, and lubricant additive. 2,4-Pentanedione is used as an intermediate, in particular for the synthesis of heterocyclic substances for biologically active compounds and dyes, and for the production of metal acetylacetonates. Furthermore, 2,4-pentanedione is used as a solvent, and as an absorption and extraction agent, particularly for the separation and purification of metal ions. Another application is for the purification of metalcontaining wastewater and for corrosion protection. 2,4-Pentanedione is also used as a component of catalyst systems for polymerization, copolymerization, oligo- and dimerization.

What are the applications of Application

Acetylacetone is an indicator for the complexometric titration of Fe(III)

Definition

ChEBI: A beta-diketone that is pentane in which the hydrogens at positions 2 and 4 are replaced by oxo groups.

What are the applications of Application

Acetylacetone, also known as 2,4-pentanedione, is an important commodity chemical and widely used as a fuel additive, as dyeing intermediate, in the fields of metal extraction, metal plating, and resin modification. Hantzsch reaction was used as a derivatizing agent for the assay of compounds having a primary amino group. The reagent was reacted with the primary amino group of the drugs to form a product having color and/or emit fluorescence. This condensation reaction was distinguished by its precision, reproducibility, and analytical cost reduction. FLX contains an aliphatic amino group, in the presence of formaldehyde solution, this amino group can condense with two equivalents of acetylacetone to form dihydropyridine derivative that emits yellow fluorescent product. (Figure1). Under optimized conditions of the reaction, FLX gave highly fluorescent product measured at λem 479 nm using 419 nm as excitation.

Production Methods

2,4-Pentanedione is produced by thermal or metal-catalyzed rearrangement of isopropenyl acetate(obtained from acetone and ketene):

Isopropenyl acetate vapor is fed at atmospheric pressure through a V2A steel tube with an inner temperature of 520℃. The hot reaction gases are quenched, condensed, and cooled to 20℃, whereby the gaseous byproducts carbon monoxide, carbon dioxide, methane, and ketene are separated. The product is purified by fractional distillation. Other industrially less important processes for the production of 2,4-pentanedione, include the Claisen ester condensation of ethyl acetate with acetone using sodium ethoxide as condensation agent and the acetylation of acetoacetic acid esters with acetic anhydride in the presence of magnesium salts.

Synthesis Reference(s)

Journal of the American Chemical Society, 102, p. 2095, 1980 DOI: 10.1021/ja00526a059
Organic Syntheses, Coll. Vol. 3, p. 17, 1955

General Description

A colorless or yellow colored liquid. Less dense than water. Flash point 105°F. Vapors are heavier than air. Used as a solvent in paints and varnishes.

Air & Water Reactions

Flammable. Soluble in water.

Reactivity Profile

Ketones, such as 2,4-Pentanedione, 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. May dissolve plastics [USCG, 1999].

Health Hazard

Inhalation causes dizziness, headache, nausea, vomiting and loss of consciousness. Contact with liquid irritates eyes.

Health Hazard

Exposures to acetyl acetone cause eye irritation, chemical conjunctivitis, corneal damage, and skin irritation (harmful if absorbed through the skin). At low concentrations for long periods, inhalation/dermal absorption of acetyl acetone causes irritation and dermatitis, cyanosis of the extremities, pulmonary edema, and a burning sensation in the chest. Ingestion/accidental ingestion in the workplace can result in gastrointestinal irritation, nausea, vomiting, diarrhea, and CNS depression. Inhalation of high concentrations may cause CNS effects characterized by nausea, headache, dizziness or suffocation, unconsciousness, and coma. The target organ of acetyl acetone poisoning has been identifi ed as the CNS.

Health Hazard

Exposure to the vapors of acetyl acetone cancause irritation of the eyes, mucous membrane, and skin. In rabbits 4.76 mg producedsevere eye irritation; the effect on skin wasmild. Other than these, the health hazardsfrom this compound have not been reported.However, based on its structure and the factthat it has two reactive carbonyl groups inthe molecule, this compound should exhibitlow to moderate toxicity at high concentrations, which should be greater than that ofthe C5-monoketones.
LD50 value, intraperitoneal (mice): 750mg/kg
LD50 value, oral (rats): 1000 mg/kg
There is no report on its carcinogenicity inanimals or humans.

Fire Hazard

Behavior in Fire: Vapor is heavier than air and may travel to a source of ignition and flash back.

Safety Profile

Poison by ingestion and intraperitoneal routes. Moderately toxic by inhalation. A skin and severe eye irritant. Experimental reproductive effects. Mutation data reported. Flammable liquid when exposed to heat or flame. Incompatible with oxidning materials. To fight fire, use alcohol foam, CO2, dry chemical.

Potential Exposure

Acetoacetic acid derivative. 2,4-Pentanedione is used in gasoline and lubricant additives, fungicides, insecticides, and colors manufacture; as a chemical intermediate and in the manufacture of metal chelates

storage

Acetylacetone should be stored away from heat, sparks, flame, and from sources of ignition. It should be stored in a tightly sealed container, in a cool, dry, well-ventilated area, away from incompatible substances.

Shipping

UN2310 Pentane-2,4-dione, Hazard Class: 3; Labels: 3-Flammable liquid

Purification Methods

Small amounts of acetic acid are removed by shaking with small portions of 2M NaOH until the aqueous phase remains faintly alkaline. The sample, after washing with water, is dried with anhydrous Na2SO4, and distilled through a modified Vigreux column (p 11) Cartledge J Am Chem Soc 73 4416 1951]. An additional purification step is fractional crystallisation from the liquid. Alternatively, there is less loss of acetylacetone if it is dissolved in four volumes of *benzene and the solution is shaken three times with an equal volume of distilled water (to extract acetic acid): the *benzene is then removed by distillation at 43-53o and 20-30mm through a helices-packed column. It is then refluxed over P2O5 (10g/L) and fractionally distilled under reduced pressure. The distillate (sp conductivity 4 x 10-8 ohm-1cm-1) is suitable for polarography [Fujinaga & Lee Talanta 24 395 1977]. To recover used acetylacetone, metal ions are stripped from the solution at pH 1 (using 100mL 0.1M H2SO4/L of acetylacetone). The acetylacetone is then washed with (1:10) ammonia solution (100mL/L) and with distilled water (100mL/L, twice), then treated as above. It complexes with Al, Be, Ca, Cd, Ce , Cu, Fe2+, Fe3+ , Mn, Mg, Ni, Pb and Zn. [Beilstein 1 H 777, 1 I 401, 1 II 831, 1 III 3113, 1 IV 3662.]

Incompatibilities

Vapors may form explosive mixture with air. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides. reducing agents; halogens, aliphatic amines; alkanolamines, organic acids; isocyanates. Strong light may cause polymerization.

Waste Disposal

Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. All federal, state, and local environmental regulations must be observed.

Precautions

Occupational workers should only use/handle acetyl acetone in a well-ventilated area, with spark-proof tools and explosion-proof equipment. Workers should not cut, weld, braze, solder, drill, grind, pressurize, or expose empty containers to heat, sparks, or flames.