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.
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| Names | |
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| 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)
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| ChEBI | |
| ChemSpider | |
| ECHA InfoCard | 100.003.400 |
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PubChem CID
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| UNII | |
| UN number | 1224 |
CompTox Dashboard (EPA)
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| 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: | |
 
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| 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
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acetylacetone |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Symptoms of poisoning
editThe 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
edit2,5-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.[3]
Synthesis
edit2,5-Hexanedione has been prepared in several ways.[4] A common method involves hydrolysis of 2,5-dimethylfuran, a glucose derived heterocycle.[1]
Uses
editAcetonylacetone can be used in the synthesis of isocarboxazid,[5] rolgamidine,[6] and mopidralazine. Treatment with P4S10 gives 2,5-dimethylthiophene.
References
edit- ^ a b Young, D. M.; Allen, C. F. H. (1936). "2,5-Dimethylpyrrole". Organic Syntheses. 16: 25. doi:10.15227/orgsyn.016.0025.
- ^ 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.
- ^ Wolfgang Dekant; Spiridon Vamvakas (2007). "Toxicology". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. p. 23. ISBN 978-3527306732.
- ^ http://www.prepchem.com/synthesis-of-2-5-hexanedione/ Primary: Systematic organic chemistry, by W. M. Cumming, 194, 1937.
- ^ U.S. patent 2,908,688
- ^ U.S. patent 4,140,793