Ethyl acetoacetate
From Wikipedia, the free encyclopedia
| Ethyl acetoacetate | |
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| IUPAC name | Ethyl 3-oxobutanoate |
| Other names | Acetoacetic acid ethyl ester Ethyl acetylacetate 3-Oxobutanoic acid ethyl ester |
| Identifiers | |
| CAS number | [141-97-9] |
| RTECS number | AK5250000 |
| SMILES | CC(=O)CC(=O)OCC |
| Properties | |
| Molecular formula | C6H10O3 |
| Molar mass | 130.14 g/mol |
| Appearance | Colourless liquid with fruit or rum odour |
| Density | 1.021 g/cm3, liquid |
| Melting point |
-45 °C (228 K) |
| Boiling point |
180.8 °C (454.0 K) |
| Solubility in water | 2.86 g/100 ml (20 °C) |
| Acidity (pKa) | 25 (in H2O) 14.2 (in DMSO) |
| Hazards | |
| EU classification | not listed |
| NFPA 704 |
 2
2
0
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| Flash point | 70 °C |
| Related compounds | |
| Related esters | Methyl acetoacetate Ethyl acetate Diethyl malonate |
| Related compounds | Acetone Acetylacetone Diketene |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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The organic compound ethyl acetoacetate (EAA) is the ethyl ester of acetoacetic acid. It is a solvent, and is used as a chemical intermediate in the production of a wide variety of compounds, such as amino acids, analgesics, antibiotics, antimalarial agents, antipyrene and aminopyrene, and vitamin B1; and also in the manufacture of dyes, inks, lacquers, perfumes, plastics, and yellow paint pigments. Alone, it is used as a flavoring for food.
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[edit] Preparation
Ethyl acetoacetate may be prepared via the Claisen condensation of ethyl acetate. Two moles of ethyl acetate condense to form one mole each of ethyl acetoacetate and ethanol.
Another method is to use acetyl ketene and ethanol. They directly form ethyl acetoacetate, and the yield is good, so this method is widely used in industry, but acetyl ketene is very dangerous.[citation needed]
[edit] Chemistry
Ethyl acetoacetate is often used in the acetoacetic ester synthesis similar to diethyl malonate in the Malonic ester synthesis or the Knoevenagel condensation. The protons alpha to carbonyl groups are easily deprotonated and then the carbanion formed can undergo nucleophilic substitution. A subsequent thermal decarboxylation is also possible.
[edit] Analysis
Ethyl acetoacetate is an ester of a β-keto carbonic acid and therefore has a strong Keto-enol tautomerism. The enolate forms purple complexes with iron(III) salts: 
[edit] See also
- Fructone, the ethylene glycol ketal of ethyl acetoacetate, an aroma compound
[edit] References
Carey, Francis A. (2006). Organic Chemistry, Sixth Edition, New York, NY: McGraw-Hill. ISBN 0-07-111562-5.
