431-03-8

Basic information

• Product Name: 2,3-Butanedione
• Synonyms: 2,3-Butanedione 2,3-Diketobutane Dimethylglyoxal;2,3-Butanedione 97%;Two2,3-butylketone;2, 3 - butyl diketone;2,3-DIOXOBUTANE;2,3-DIKETOBUTANE;2,3-BUTANEDIONE;2,3-BUTADIONE
• CAS NO: 431-03-8
• Molecular Formula: C₄H₆O₂
• Molecular Weight: 86.09
• EINECS: 207-069-8
• Product Categories: Ketones;Organic Building Blocks;Organics;Biochemistry;Reagents for Oligosaccharide Synthesis;ketone Flavor;B;Bioactive Small Molecules;Building Blocks;C3 to C6;Carbonyl Compounds;Cell Biology;Chemical Synthesis
• Mol File: 431-03-8.mol
• Article Data: 158

Chemical Properties

• Melting Point: -4--2 °C
• Boiling Point: 88 °C(lit.)
• Flash Point: 45 °F
• Appearance: Clear yellow/Liquid
• Density: 0.985 g/mL at 20 °C
• Vapor Density: 3 (vs air)
• Vapor Pressure: 52.2 mm Hg ( 20 °C)
• Refractive Index: n20/D 1.394(lit.)
• Storage Temp.: 2-8°C
• Solubility: 200g/l
• Explosive Limit: 2.4-13.0%(V)
• Water Solubility: 200 g/L (20 ºC)
• Stability: Stable. Flammable. Incompatible with acids, strong bases, metals, reducing agents, oxidizing agents. Protect from moisture and w
• Merck: 14,2966
• BRN: 605398
• CAS DataBase Reference: 2,3-Butanedione(CAS DataBase Reference)
• NIST Chemistry Reference: 2,3-Butanedione(431-03-8)
• EPA Substance Registry System: 2,3-Butanedione(431-03-8)

Safety Data

• Hazard Codes: F,Xn
• Statements: 11-20/22-38-41-36/38-20/21/22-37/38
• Safety Statements: 9-16-26-37/39-36/37/39-39
• RIDADR: UN 2346 3/PG 2
• WGK Germany: 2
• RTECS: EK2625000
• F: 13
• TSCA: Yes
• HazardClass: 3
• PackingGroup: II
• Hazardous Substances Data: 431-03-8(Hazardous Substances Data)

Usage

Description

2,3-Butanedione, also known as Diacetyl, is a reactive diketone in artificial butter flavors. It is a water-soluble and volatile, alpha-diketone compound that has a buttery odor. Diacetyl occurs naturally in plants, fruits, coffee, honey, cocoa, and dairy products. It is a natural by-product of fermentation and is found in beer and wine. Diacetyl is also present in cigarette smoke.

Uses

Used in Food Industry:
2,3-Butanedione is used as a flavoring agent for imparting a buttery flavor to various food products. It is used in the preparation of food essences like cream, cheese fermentation, and coffee-type essences. It is also used in milk, butter, margarine, cheese, sweets, and other flavors such as berry, caramel, chocolate, coffee, cherry, vanilla bean, honey, cocoa, fruit, wine, aroma, rum, nuts, almonds, ginger, and more.
Used in Cosmetic Industry:
2,3-Butanedione is used as a fresh fruit fragrance essence in makeup or new types of essences in trace amounts.
Used in Gelatin Hardening:
2,3-Butanedione serves as a gelatin hardening agent in the production of certain products.
Used in Photographic Adhesives:
2,3-Butanedione functions as a photographic adhesive agent, contributing to the bonding process in photographic materials.
Used in Enzyme Inactivation:
2,3-Butanedione is used to inactivate aminopeptidase-N, which is a precursor to α-diones.
Used in Chemical Synthesis:
2,3-Butanedione is utilized in cyclocondensation with amines to form triazine and pteridine ring systems, which are important in various chemical applications.

Content analysis

The content of 2,3-Butanedione is analyzed according to method 1(hydroxylamine method) of the aldehyde and ketone analyzing methods (OT-7). The sample weight is 500mg. The equivalent factor (e) in calculation is 21.52 .It is Fit to be analyzed using nonpolar column in GT-10-4.

Toxicity

Not specified by ADI (FAO/WHO，1994) GRAS(FEMA；FDA，§184．1278，2000)

Quantity restrictions

FEMA(mg/kg)： FEMA(mg/kg)：soft drinks 2.5；cold drinks 5.9；sweets 21；bakery products44； puddings 19；chewing gum 35；shortening 11.

Production

In nature, Diacetyl exists widely in many Plant essential oils, such as iris oil, angelica oil, laurel oil, etc. It is the main component of butter and other natural products fragrance. In industry, methyl ethyl ketone was treated with nitrite acid to generate diacetylmonoxime. Diacetylmonoxime is then decomposed by sulfuric acid to produce Butanedione. Diacetyl can be obtained by chemical ionization method from high content of essential oil. Two parts of phosphoric acid were added to one part of essential oil to produce crystalline adduct CH3CO-COCH3. Butanedione was released after the addition of water. Excessive addition of phosphoric acid will lead to liquid adduct product. Diacetyl can be obtained by special fermentation of glucose. Diacetyl can be synthesized using methyl ethyl ketone as raw material. Diacetyl was oxidized by sodium nitrite in the presence of hydrochloric acid, Then, the process of istillation is carried out after hydrolysis in the presence of sulfuric acid to produce Butanedione.

Preparation

From methyl ethyl ketone by converting to the isonitroso compound and then decomposing to diacetyl by hydrolysis with HCl; by fermentation of glucose via methyl acetyl carbinol.

Air & Water Reactions

Highly flammable. Soluble in water.

Reactivity Profile

2,3-Butanedione is a flammable liquid, b.p. 88° C, moderately toxic. When heated to decomposition 2,3-Butanedione emits acrid smoke and fumes [Sax, 9th ed., 1996, p. 544].

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.

Toxicology

Diacetyl is an intensely yellowish or greenish-yellow mobile liquid. It has a very powerful and diffusive, pungent, buttery odor and typically used in flavor compositions, including butter, milk, cream, and cheese. Diacetyl was found to be mutagenic in Ames test conducted under various different conditions with Salmonella typhimurium strains. For example, diacetyl was mutagenic by TA100 in the absence of S9 metabolic activation at doses up to 40 mM/plate. It was mutagenic in a modified Ames assay in Salmonella typhimurium strains TA100 with and without S9 activation. The acute oral LD50 of diacetyl in guinea pigs was calculated to be 990 mg/kg. The acute oral LD50 of diacetyl in male rats was calculated to be 3400 mg/kg, and in female rats, the LD50 was calculated to be 3000 mg/kg. When male and female rats were administered via gavage a daily dose of 1, 30, 90, or 540 mg/kg/day of diacetyl in water for 90 days, the high-dose produced anemia, decreased weight gain, increased water consumption, increased leukocyte count, and an increase in the relative weights of liver, kidneys, and adrenal and pituitary glands. The data for teratogenicity and carcinogenicity are not available. Although the FDA has affirmed diacetyl GRAS as a flavoring agent, low molecular weight carbonyls, such as formaldehyde, acetaldehyde, and glyoxal have been reported to possess a certain chronic toxicity.

Safety Profile

A poison by ingestion and intraperitoneal routes. A skin irritant. Human inhalation hazard in popcorn manufacture. Human mutation data reported. Flammable liquid. Dangerous fire hazard when exposed to heat or flame. To fight fire, use alcohol foam, CO2, dry chemical. When heated to decomposition it emits acrid smoke and fumes. See also KETONES.

Carcinogenicity

Diacetyl was tested for its ability to induce primary lung tumors in strain A/He mice. The mice received three IP injections of diacetyl per week for 8 weeks and were killed 24 weeks after the first injection. The total dose of diacetyl given was 1.7 or 8.4 g/kg. The number of lung tumors in diacetyl exposed mice was not significantly different from the control mice.Inhalation carcinogenicity bioassays withWistar Han rats and B6C3F1 mice at exposure levels of 0, 12.5, 25, and 50 ppm are underway according to the National Toxicology Program.

Environmental Fate

Mechanisms of diacetyl-induced toxicity are not known, but some possible mechanisms of toxicity have been postulated. The adjacent carbonyl groups on diacetyl make it a reactive compound. In vitro studies have demonstrated that diacetyl can bind to arginine and inactivate proteins. The electron affinity of diacetyl suggests that it can undergo electron transfer activity, which can lead to oxidative stress by oxygen redox cycling. Redox cycling and oxidative stress may also be initiated during metabolism of diacetyl by DCXR (dicarbonyl/L-xylulose reductase). Reactive oxygen species are known to be produced from metabolic activation of dicarbonyl substrates by related carbonyl reductase enzymes in the presence of O2.

Purification Methods

Dry biacetyl over anhydrous CaSO4, CaCl2 or MgSO4, then distil it in a vacuum under nitrogen, taking the middle fraction and storing it at Dry-Ice temperature in the dark (to prevent polymerization). [Beilstein 1 IV 3644.]

Toxicity evaluation

Diacetyl released to the environment is expected to be highly mobile in soil and is not expected to adsorb to suspended sediments and solids in water. Diacetyl is degraded by a bacterium tentatively identified as Pseudomonas. Bioconcentration of diacetyl by aquatic organisms is not likely. Diacetyl is expected to volatilize from soil and water surfaces, and diacetyl is likely to exist solely as a vapor in the ambient atmosphere. In the atmosphere, diacetyl is degraded by photochemically produced hydroxyl radicals and it undergoes photolysis.

InChI:InChI=1/C4H6O2/c1-3(5)4(2)6/h1-2H3

Upstream product

• 110-86-1 pyridine 
• 56-84-8 L-Aspartic acid 
• 108-24-7 acetic anhydride 
• 609-14-3 2-acetylpropanoic acid ethyl ester 
• 50-00-0 formaldehyd 
• 3588-31-6 2,3-dimethoxy-1,3-butadiene 
• 2648-69-3 3,3-dibromobutan-2-one 
• 107-01-7 butene-2 
• 4461-41-0 2-chloro-but-2-ene 
• 29027-51-8 diacetyldioxime monomethylether 
• 29144-51-2 (MeON=C(Me)-CMe=NOMe) 
• 50-99-7 glucose 
• 87-69-4 L-Tartaric acid 
• 67-66-3 chloroform 

Downstream Products

• 92152-08-4 (1E,5E)-1,6-di(furan-2-yl)hexa-1,5-diene-3,4-dione 
• 7154-32-7 dimethyl-2,3 pyrido<2,3-b>pyrazine 
• 16042-70-9 butane-2,3-dione bis(2′-pyridylhydrazone) 
• 103262-24-4 6,7,8-trimethyl-8H-pteridin-4-one 
• 103262-23-3 6,7,8-Trimethyl-2-oxo-2,8-dihydro-pteridin 
• 1425-63-4 6,7-dimethyl-2,4-pteridine-2,4-diamine 
• 14684-54-9 6,7-dimethylpteridin-4(3H)-one 
• 60-35-5 acetamide 
• 4217-65-6 (R,S)-2,3-diphenylbutane-2,3-diol 
• 22985-90-6 (2R,3R)-2,3-Diphenyl-butane-2,3-diol 
• 13866-99-4 butane-2,3-dione-mono-(methyl-phenyl-hydrazone) 
• 181707-44-8 butane-2,3-dione-bis-(4-dimethylamino-phenylimine) 
• 15986-92-2 5,6-dimethyl-2,3-dihydropyrazine 
• 5910-89-4 2,3-dimethylpyrazine 

Relevant articles and documents

-

-

-

-

AZIRINYL AND DIAZIRINYL (CHLORIDE) ION PAIRS AS INTERMEDIATES

Both ab initio calculations and experimental observations support the intermediacy of diazirinyl or azirinyl cation-chloride anion pairs in transformations (1), (2), and (4).

-

-

-

-

Reaction Kitenics in Acetyl Chemistry over a Wide Range of Temperature and Pressure

The molecular modulation spectrometer has been used to study the complex chemical kitenics involed in acetyl radical chemistry.This has involved direct monitoring of both acetyl and methyl radicals in the same experiment and over a variety of temperatures (263 /1019 molecule cm-3 = 2.7) conditions.These measurements have been complemented by a non-linear least-squares analysis of the experimental data and simple product studies.Rate data on four reactions and the absorption cross-section of the acetyl radical at 223 nm have been determined in this way.Unimolecular rate theory, based on Kassel integrals, has been applied to the pressure-dependent formation and decay of the radical to extract limiting values for the rate constants at T = 303 and 343 K.

Synthesis of 2,3-butanedione over TS-1, Ti-NCl, TiMCM-41, Ti-Beta, Fe-Si, Fe-Beta and VS-1 zeolites

The purpose of this work is the synthesis of 2,3-butanedione (diacetyl) by selective oxidation of 2-butanone (methyl ethyl ketone) in the presence of O2 and H2O2 30% as oxidants. All the tests were performed over several selective oxidation zeolite catalysts, synthesized and characterized in our laboratory.

Synthesis of Dialkyl- and Alkylacylrhenium Complexes by Alkylation of Anionic Rhenium Complexes at the Metal Center. Mechanism of a Double Carbonylation Reaction That Proceeds via the Formation of Free Methyl Radicals in Solution

The site of alkylation of salts of acylrhenates such as Li(1+)(1-) (1) can be controlled by adjusting the hardness of the alkylating agent.Thus, treatment of 1 with the hard alkylating agent (CH3)3OPF6 gives predominantly the clssical Fischer carbene complex Cp(CO)2Re=C(OCH3)(CH3) (2), whereas reaction with the softer electrophile CH3I leads almost exclusively to the new metal-alkylated complex Cp(CO)2Re(CH3)(COCH3) (3).The structure of 3 has been determined by X-ray diffraction.The availability of this material, a relatively rare example of astable alkylacylmetal complex, has provided an opportunity to study the products and mechanisms of its carbon-carbon bond-forming decomposition reactions.Thermally, the alkyl acyl complex undergoes simple reductive elimination, leading (in the presence of a metal-scavenging ligand L) to a quantitative yield of acetone and CpRe(CO)2(L).Photochemically, a more complicated reaction takes place, especially under 20 atm of CO, where CpRe(CO)3 and 2,3-butanedione are formed.Strikingly, irradiation of Cp(CO)2Re(CH3)2 (9) under 20 atm of CO gives products identical with those formed from 3.Labeling experiments using (13)CO and mixtures of acetyl- and propionylrhenium complexes are inconsistent with a mechanism involving simple migratory CO insertion followed by reductive elimination.They are, however, consistent with metal-carbon bond homolysis leading to methyl and acetyl radicals, followed by carbonylation of the methyl radicals to give a second source of acetyl radicals; these reactive intermediates then dimerize to give 2,3-butanedione.Confirmation of this mechanism was obtained by trapping all the initially formed radicals withhalogen donors.BrCCl3, proved to be much more efficient than CCl4 for this purpose: irradiation of alkyl acyl complex 3 in the presence of BrCCl3 diverted the reaction completely from 2,3-butanedione production, giving instead CH3Br, CH3COBr, Cp(CO)2Re(CH3)Br, and Cp(CO)2Re(CH3CO)Br.

-

-

OXIDATION OF ALIPHATIC KETONES BY BROMAMINE-B: A KINETIC STUDY

The kinetics of oxidation of propan-2-one, butan-2-one, pentan-2-one, pentan-3-one and 4-methyl pentan-2-one by sodium N-bromobenzenesulphonamide or bromamine-B (BAB) in perchloric acid medium was studied at 30 deg C.The rate shows a first order dependence each on and +> and is independent of .Variation of ionic strength of medium and addition of the reaction product benzenesulphonamide have no effect on the rate and the dielectric effect is positive.The proposed mechanism involves acid catalysed enolisation of ketone in the rate limiting step followed by a fast interaction with the oxidant.This is supported by the magnitude of inverse solvent isotope effect of 1.62 +/- 0.01 observed in D2O medium.Activation parameters Ea, ΔH*, ΔS*, ΔG* and log A have been calculated by studying the reaction at different temperatures (293-309 K).

-

-

Atmospheric Chemistry of Selected Hydroxycarbonyls

Using a relative rate method, rate constants have been measured at 296 ± 2 K for the gas-phase reactions of the OH radical with 1-hydroxy-2-butanone, 3-hydroxy-2-butanone, 1-hydroxy-3-butanone, 1-hydroxy-2-methyl-3-butanone, 3-hydroxy-3-methyl-2-butanone, and 4-hydroxy-3-hexanone, with rate constants (in units of 10-12 cm3 molecule-1 s-1) of 7.7 ± 1.7, 10.3 ± 2.2, 8.1 ± 1.8, 16.2 ± 3.4, 0.94 ± 0.37, and 15.1 ± 3.1, respectively, where the error limits include the estimated overall uncertainty in the rate constant for the reference compound. Rate constants were also measured for reactions with NO3 radicals and O3. Rate constants for the NO3 radical reactions (in units of 10-16 cm3 molecule-1 s-1) were 1-hydroxy-2-butanone, 3 were observed, and upper limits to the rate constants of -19 cm3 molecule-1 s-1 were derived for all six hydroxycarbonyls. The dominant tropospheric loss process for the hydroxycarbonyls studied here is calculated to be by reaction with the OH radical.

-

-

Photo-oxidations of Acetoin and Biacetyl catalyzed by Tetrabutylammonium Decatungstate(4-) in Acetonitrile under Excess of Oxygen

Under an excess of oxygen, the photo-oxidation of acetoin catalysed by (NBu4)4(W10O32) and based on irradiation (λ > 300 nm) of the charge-transfer band in acetonitrile solution has been investigated.After irradiating for 30 h the products were biacetyl and acetic acid.The acetic acid was produced from both the acetoin and biacetyl.The rate constant for each path was determined by computer simulation.The production of biacetylis based on dehydrogenation of acetoin in conjunction with the redox cycle of (W10O32)4- attained by reaction with O2, whereas the production of acetic acid from biacetyl is based on the photoexcitation of biacetyl complexed with (W10O32)4- and subsequent reactions with O2 and water.

-

-

Sol-gel synthesis of ceria-zirconia-based high-entropy oxides as high-promotion catalysts for the synthesis of 1,2-diketones from aldehyde

Efficient Lewis-acid-catalyzed direct conversion of aldehydes to 1,2-diketones in the liquid phase was enabled by using newly designed and developed ceria–zirconia-based high-entropy oxides (HEOs) as the actual catalysts. The synergistic effect of various cations incorporated in the same oxide structure (framework) was partially responsible for the efficiency of multicationic materials compared to the corresponding single-cation oxide forms. Furthermore, a clear, linear relationship between the Lewis acidity and the catalytic activity of the HEOs was observed. Due to the developed strategy, exclusively diketone-selective, recyclable, versatile heterogeneous catalytic transformation of aldehydes can be realized under mild reaction conditions.

Bioinspired oxidation of oximes to nitric oxide with dioxygen by a nonheme iron(II) complex

The ability of two iron(II) complexes, [(TpPh2)FeII(benzilate)] (1) and [(TpPh2)(FeII)2(NPP)3] (2) (TpPh2 = hydrotris(3,5-diphenylpyrazol-1-yl)borate, NPP-H = α-isonitrosopropiophenone), of a monoanionic facial N3 ligand in the O2-dependent oxidation of oximes is reported. The mononuclear complex 1 reacts with dioxygen to decarboxylate the iron-coordinated benzilate. The oximate-bridged dinuclear complex (2), which contains a high-spin (TpPh2)FeII unit and a low-spin iron(II)–oximate unit, activates dioxygen at the high-spin iron(II) center. Both the complexes exhibit the oxidative transformation of oximes to the corresponding carbonyl compounds with the incorporation of one oxygen atom from dioxygen. In the oxidation process, the oxime units are converted to nitric oxide (NO) or nitroxyl (HNO). The iron(II)–benzilate complex (1) reacts with oximes to afford HNO, whereas the iron(II)–oximate complex (2) generates NO. The results described here suggest that the oxidative transformation of oximes to NO/HNO follows different pathways depending upon the nature of co-ligand/reductant.