1540-38-1

Basic information

• Product Name: 3-(1-methylethyl)pentane-2,4-dione
• Synonyms: 3-(1-methylethyl)pentane-2,4-dione;3-(1-Methylethyl)-2,4-pentanedione;3-propan-2-ylpentane-2,4-dione
• CAS NO: 1540-38-1
• Molecular Formula: C₈H₁₄O₂
• Molecular Weight: 142.19556
• EINECS: 216-275-7
• Mol File: 1540-38-1.mol
• Article Data: 6

Chemical Properties

• Boiling Point: 190.8°Cat760mmHg
• Flash Point: 66.7°C
• Appearance: /
• Density: 0.913g/cm³
• Vapor Pressure: 0.532mmHg at 25°C
• Refractive Index: 1.416
• CAS DataBase Reference: 3-(1-methylethyl)pentane-2,4-dione(CAS DataBase Reference)
• NIST Chemistry Reference: 3-(1-methylethyl)pentane-2,4-dione(1540-38-1)
• EPA Substance Registry System: 3-(1-methylethyl)pentane-2,4-dione(1540-38-1)

Safety Data

• Hazardous Substances Data: 1540-38-1(Hazardous Substances Data)

Usage

General Description

3-(1-methylethyl)pentane-2,4-dione, also known as diacetyl, is a chemical compound with the molecular formula C6H10O2. It is a volatile and flammable liquid with a strong, buttery odor. Diacetyl is commonly used as a flavoring agent in food products, particularly in buttery or creamy flavors. It is also a natural byproduct of fermentation and is found in some alcoholic beverages. However, diacetyl has been linked to respiratory issues and is a known cause of "popcorn lung" when inhaled in high concentrations. As a result, its use as a flavoring agent has been heavily regulated in many countries.

InChI:InChI=1/C8H14O2/c1-5(2)8(6(3)9)7(4)10/h5,8H,1-4H3

Upstream product

• 108-24-7 acetic anhydride 
• 5435-44-9 (E)-3-Ureido-but-2-enoic acid ethyl ester 
• 108-10-1 4-methyl-2-pentanone 
• 1541-03-3 cis-CH₃COOC(CH₃)CHCH(CH₃)2 
• 7637-07-2 boron trifluoride 
• 75-26-3 isopropyl bromide 
• 123-54-6 acetylacetone 
• 187737-37-7 propene 
• 75-30-9 2-iodo-propane 
• 917-64-6 methyl magnesium iodide 
• 15181-39-2 3-ethylidene-pentane-2,4-dione 
• 5185-89-7 (3-acetyl-2-methyl-4-oxo-pentyl)-chloro-mercury 
• 15435-71-9 sodium acetylacetonate 

Downstream Products

• 98885-97-3 (1E,6E)-1,7-Bis-(4-hydroxy-3-methoxy-phenyl)-4-isopropyl-hepta-1,6-diene-3,5-dione 
• 98886-05-6 (1E,6E)-1,7-Bis-(3,4-dimethoxy-phenyl)-4-isopropyl-hepta-1,6-diene-3,5-dione 
• 38664-17-4 3-(4-acetyl-5-methyl-1H-pyrrol-3-yl)propanoic acid 

Relevant articles and documents

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Catalytic hydroalkylation of olefins by stabilized carbon nucleophiles promoted by dicationic platinum(II) and palladium(II) complexes

The coordinated olefin in dicationic platinum(II) and palladium(II) complexes [M(PNP)(olefin)](SbF6)2 (M = Pt, Pd; PNP = 2,6-bis(diphenylphosphinomethyl)pyridine; olefin = ethylene, propylene) reacts with β-dicarbonyl compounds (pentane-2,4-dione and methyl-3-oxobutanoate). If the proton released after the nucleophilic attack is trapped by a base, stable σ-alkyl derivatives [(PNP)M-CH2-CH(R)CH(Ac)COR′] SbF6 (R = H, Me; R′ = Me, OMe) are formed; otherwise the M-C σ-bond can be cleaved by the proton, in the rate-determining step of a catalytic cycle that leads to the alkylated dicarbonyl compound. The β-diketone is intrinsically more reactive than the β-ketoester, but in the catalytic reaction of the former an inhibition effect is observed in the case of the platinum catalyst.

Use of the Nonionic Superbase P(MeNCH2CH2)3N in the Selective Monoalkylation of Active-Methylene Compounds

The symmetric active-methylene compounds CH2(CO2Et)2 and CH2[C(O)Me]2 are selectively monoalkylated in the presence of 1.1 equiv of a variety of alkyl halides and 1 equiv of the nonionic Superbase P(MeNCH2CH2)2N in 85-98% yields in 30 min at room temperature. The unsymmetrical active-methylene compound EtO2CCH2C(O)Me is selectively monoalkylated under the same conditions, except for the temperature, which is 0 °C, in 59-88% yields. The observation of selective C- rather than O-alkylation is rationalized in terms of the formation of an enolate whose negatively charged oxygen is sterically protected by a nearby HP(MeNCH2CH2)2N+ counterion in a tight ion pair.