Коричная кислота: свойства, получение и применение

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|Verifiedfields = changed
|Watchedfields = changed
|verifiedrevid = 476994181
|Name = Cinnamic acid
|ImageFile = Zimtsäure Cinnamic acid. svg
|ImageName = Skeletal formula of trans cinnamic acid
|ImageFile1 = Cinnamic acid 3D ball. png
|ImageName1 = Ball and stick model of the trans cinnamic acid molecule
|ImageFile2 = Cinnamic acid. jpg
|ImageName2 = Sample of the compound cinnamic acid in powder form
|PIN = (2E) 3 Phenylprop 2 enoic acid
|SystematicName = Cinnamic acid
|OtherNames = trans Cinnamic acidPhenylacrylic acidCinnamylic acid3 Phenylacrylic acid(E) Cinnamic acidBenzenepropenoic acidIsocinnamic acid
|Section1=
|Section2=Chembox Properties
|C=9 | H=8 | O=2
|Appearance = White monoclinic crystals
|Odor = Honey like
|Solubility = 500 mg/L
|Density = 1.2475 g/cm3

It is obtained from oil of cinnamon, or from balsams such as storax. It is also found in shea butter. Cinnamic acid has a honey like odor; and its more volatile ethyl ester, ethyl cinnamate, is a flavor component in the essential oil of cinnamon, in which related cinnamaldehyde is the major constituent. It is also found in wood from all species of trees.

Cinnamic acid was first synthesized by the base catalysed condensation of acetyl chloride and benzaldehyde, followed by hydrolysis of the acid chloride product. In 1890, Rainer Ludwig Claisen described the synthesis of ethyl cinnamate via the reaction of ethyl acetate with benzaldehyde in the presence of sodium as base. Another way of preparing cinnamic acid is by the Knoevenagel condensation reaction. The reactants for this are benzaldehyde and malonic acid in the presence of a weak base, followed by acid catalyzed decarboxylation. It can also be prepared by oxidation of cinnamaldehyde, condensation of benzal chloride and sodium acetate (followed by acid hydrolysis), and the Perkin reaction. The oldest commercially used route to cinnamic acid involves the Perkin reaction, which is given in the following scheme]]

Cinnamic acid, obtained from autoxidation of cinnamaldehyde, is metabolized into sodium benzoate in the liver.

Cinnamic acid is used in flavorings, synthetic indigo, and certain pharmaceuticals. A major use is as a precursor to produce methyl cinnamate, ethyl cinnamate, and benzyl cinnamate for the perfume industry.