Diethyl malonate

• Diethyl malonate
• Malonic ester

Colorless liquid with aromatic odor

Liquid

1.06 g · cm -3

-50 ° C

1.3 hPa ( 20 ° C)

Slightly soluble in almost all organic solvents, slightly soluble in water

1.414 (20 ° C)

Attention

• > 16,000 mg · kg -1 ( LD50, Rabbit, transdermal)
• 15,000 mg · kg -1 ( LD50, rat, oral)

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Diethyl malonate is a colorless pleasant -smelling liquid, which is one of the esters.

Production and representation

Malonate can not be obtained from the free acid by esterification with ethanol because malonic acid at elevated temperatures to give acetic acid and CO2 is divided ( decarboxylation). To prepare the potassium salt of cyanoacetic acid with ethanol and concentrated mineral acids must be implemented.

Properties

The methylene protons of the diethyl malonate are slightly acid; therefore, it can be deprotonated with strong bases such as sodium ethoxide. This deprotonated form a carbanion, and can be reacted with alkyl halides to alkyl Malonsäurediethylestern ( malonic ester synthesis). Other possible reactions of this carbanion:

• Reaction with carbonyl compounds (aldehydes or ketones) leads to aldol
• Reaction with carboxylic acid derivatives leads to the acylation

Use

Alkyl-substituted malonate hydrolyzed to the corresponding alkylated malonic acids and then heated, they undergo decarboxylation as the malonic acid itself; it arise under carbon dioxide elimination substituted acetic acid derivatives. Alkyl-substituted malonate can be further reacted with urea to barbituric acid derivatives. The reaction is related to the Knoevenagel reaction.