Hexane-2,5-dione

(Redirected from Acetonylacetone)

2,5-Hexanedione (Acetonylacetone) is an aliphatic diketone. It is a colorless liquid.[1] In humans, it is a toxic metabolite of hexane and of 2-hexanone.

Hexane-2,5-dione
Skeletal formula of hexane-2,5-dione
Names
Preferred IUPAC name
Hexane-2,5-dione
Other names
1,2-Diacetylethane
'α','β'-Diacetylethane
Acetonyl acetone
Diacetonyl
2,5-Dioxohexane
2,5-Diketohexane
2,5-Hexanedione
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.003.400 Edit this at Wikidata
EC Number
  • 203-738-3
RTECS number
  • MO3150000
UNII
UN number 1224
  • InChI=1S/C6H10O2/c1-5(7)3-4-6(2)8/h3-4H2,1-2H3 checkY
    Key: OJVAMHKKJGICOG-UHFFFAOYSA-N checkY
  • InChI=1/C6H10O2/c1-5(7)3-4-6(2)8/h3-4H2,1-2H3
    Key: OJVAMHKKJGICOG-UHFFFAOYAH
  • O=C(C)CCC(=O)C
Properties
C6H10O2
Molar mass 114.1438 g mol−1
Appearance colorless liquid
Density 0.973 g cm−3, liquid
Melting point −5.5 °C (22.1 °F; 267.6 K)
Boiling point 191.4 °C (376.5 °F; 464.5 K)
≥ 10 g/100 mL (22 °C)
-62.51·10−6 cm3/mol
Structure
trigonal planar at carbonyl
tetrahedral elsewhere
Hazards
GHS labelling:
GHS07: Exclamation markGHS08: Health hazard
Warning
H315, H319, H373
P260, P264, P280, P302+P352, P305+P351+P338, P314, P321, P332+P313, P337+P313, P362, P501
Flash point 78 °C (172 °F; 351 K)
Related compounds
Related diketones
acetylacetone
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Symptoms of poisoning

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The chronic toxicity of hexane is attributed to hexane-2,5-dione. The symptoms are tingling and cramps in the arms and legs, followed by general muscular weakness. In severe cases, atrophy of the skeletal muscles is observed, along with a loss of coordination and vision problems.[2]

Similar symptoms are observed in animal models. They are associated with a degeneration of the peripheral nervous system (and eventually the central nervous system), starting with the distal portions of the longer and wider nerve axons.

Mechanism of action

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It appears that the neurotoxicity of 2,5-hexanedione resides in its γ-diketone structure since 2,3-, 2,4-hexanedione and 2,6-heptanedione are not neurotoxic, whereas 2,5-heptanedione and 3,6-octanedione and other γ-diketones are.[3]

2,5-Hexanedione reacts with lysine residues in axonal proteins by Schiff base formation followed by cyclization to give pyrroles. Oxidation of the pyrrole residues then causes cross-linking and denaturation of proteins, which perturbs axonal transport and function and causes damage to nerve cells.[4]

Synthesis

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2,5-Hexanedione has been prepared in several ways.[5] A common method involves hydrolysis of 2,5-dimethylfuran, a glucose derived heterocycle.[1]

Uses

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Acetonylacetone can be used in the synthesis of isocarboxazid,[6] rolgamidine,[7] and mopidralazine. Treatment with P4S10 gives 2,5-dimethylthiophene.

References

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  1. ^ a b Young, D. M.; Allen, C. F. H. (1936). "2,5-Dimethylpyrrole". Organic Syntheses. 16: 25. doi:10.15227/orgsyn.016.0025.
  2. ^ Couri D, Milks M. "Toxicity and metabolism of the neurotoxic hexacarbons n-hexane, 2-hexanone, and 2,5-hexanedione" Annu. Rev. Pharmacol. Toxicol. 1982;22:145-66.
  3. ^ Stephen R Clough; Leyna Mulholland (2005), "Hexane", Encyclopedia of Toxicology, vol. 2 (2nd ed.), Elsevier, pp. 522–525
  4. ^ Wolfgang Dekant; Spiridon Vamvakas (2007). "Toxicology". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. p. 23. ISBN 978-3527306732.
  5. ^ http://www.prepchem.com/synthesis-of-2-5-hexanedione/ Primary: Systematic organic chemistry, by W. M. Cumming, 194, 1937.
  6. ^ U.S. patent 2,908,688
  7. ^ U.S. patent 4,140,793