In what substances is natural cinnamic acid found?
Both cis-cinnamic acid and trans-cinnamic acid exist in nature. The trans-form exists in essential oils such as styrax balsam, cinnamon oil, Peru balsam, basil oil, and cocoa leaf. The cis form exists in Galangal oil of Malacca. It is more stable than the cis form, and most commercially available products are trans forms.
What is the solubility of cinnamic acid in water, ether, ethanol and other substances?
Cinnamic acid has two isomers, cis and trans, and there are three kinds of homogeneous polycrystals in the cis-isomer.
The first crystal form of the cis-body is called allocinnamic acid, which precipitates from water as monoclinic crystals, colorless to white prismatic crystals; relative density 1.284 (4°C); melting point 42°C; boiling point 265°C (decomposition ), 125°C (2.533×103Pa); slightly soluble in water (0.937 at 25°C), easily soluble in ethanol, ether and ethyl acetate.
The second crystal form is called α-isocinnamic acid; the one separated from ligroin is monoclinic, colorless to white prismatic crystals; melting point 58°C; boiling point 265°C; soluble in ethanol, acetic acid, chloroform and acetone, Soluble in ether.
The third crystal form is called β-isocinnamic acid; monoclinic crystal system, colorless to white prismatic crystals; melting point 68°C; soluble in ethanol, ether, acetic acid, chloroform and acetone.
