Ethyl acetoacetate

• Ethyl acetoacetate
• Ethyl acetoacetate
• Ethyl- 3- oxobutyrate
• 3- oxobutanoic acid ethyl ester

Colorless liquid with a fruity odor

Liquid

1.03 g · cm -3 ( 20 ° C)

-44 ° C

180 ° C.

1 hPa (20 ° C)

Moderately in water ( 125 g · l-1 at 20 ° C)

1.4171 (20 ° C)

Attention

Not yet classified

Template: Infobox chemical / molecular formula search available

Acetoacetic esters is a chemical compound selected from the group of carboxylic acid esters, specifically, the ethyl ester of 3- oxobutanoic acid.

Production

Technical processes produce acetoacetic ester from ethanol and diketene.

Another way is the Claisen condensation of ethyl acetate. It was first shown by Johannes Wislicenus.

Properties

Acetoacetic ester is a colorless, slightly oily liquid. The activated methylene group between the two carbonyl groups is very reactive and can be alkylated, acylated and halogenate. So functionalized Acetessigesterderivate can be cleaved with concentrated liquor into carboxylic acids and acids with a ketone forms.

Acetoacetic ester shows a pronounced keto -enol tautomerism ( lie 46 % of the acetoacetic ester in n- hexane as the enol ago).

It is a C -H -acidic compound, pKa = 11, since the enolate anion is strongly resonance-stabilized.

Use

Acetoacetic ester is by the functional groups output for organic syntheses such as the Hantzschsche dihydropyridine and the Japp - Klingemann reaction. It is also used as the solvent.

Analysis

Iron (III ) chloride solution turns an aqueous Acetessigesterlösung violet by complex formation:

The reaction is not specific, as other enolizable β - keto carboxylic acids (such as salicylic acid ), and their esters exhibit the same reaction.

Acetoacetic ester is used in building materials analysis for the determination of free calcium oxide (CaO ) in fly ash or cement. (Determined by Franke )