CINNAMON. 199 
with ether *. Piria obtained it by the distillation of a mixture of 
calcium cinnamate and calcium formate f. 
Cinnamic acid was so named by Dumas and Peligot in 1884, who 
found that oil of cinnamon bears the same relation to it as oil of 
bitter almonds or benzoyl hydride to benzoic acid, and therefore 
gave it the name of cinnamyl hydride{. It also occurs in the 
so-called “ flowers ” of cinnamon, the unripe fruits of “ bastard 
cinnamon ” (Cassia) §. . 
Cinnamic acid occurs in liquid styrax, partly in the free state 
and partly as styracin or cinnyl cinnamate. The balsams of Peru 
and Tolu contain this acid in the free state and accompanied by 
the benzyl ether of cinnamic and benzoic acids. Both these acids 
have also been found in Sumatra benzoin. Cinnamic acid also 
occurs in the leaves of the Japanese garden plant, Enkyanthus 
Japonicus ||, and has been found in Globularia alypum and Globu- 
laria vulgaris ¥. 
Cinnamic acid can be obtained synthetically by heating benz- 
aldehyde with acetyl chloride to 120-130°**. It is also formed 
when benzaldehyde and glacial acetic acid are heated together to 
16° in presence of hydrochloric acid or zine chloride++. Perkin 
found that the acids of the cinnamic series may be synthetically 
prepared by heating benzaldehyde with the anhydride of a fatty 
acid and the anhydrous sodium salt of the fatty acid. In order 
to prepare cinnamic acid in this way, a mixture of 1 part of 
‘sodium acetate, 2 parts of benzaldehyde, and 3 parts of acetic 
anhydride is boiled for a day, or heated for 5 to 6 hours in a 
sealed tube at 180°. The product is boiled with water to volatilize 
any unaltered benzaldehyde, and the impure cinnamic acid, which 
crystallizes out on cooling, is washed and dissolved in hot sodium- 
carbonate solution; the liquid is allowed to cool and is then 
filtered in order to remove any oily impurity, the cimnamic acid 
being precipitated with hydrochloric acid and finally crystallized 
* Peine, Ber. Deutsch. chem. Ges. xvii. p. 2117. 
+ Ann. Chem. Pharm. c. p. 104. 
{ Ann. Chem. Pharm. xiy. p. 50, and Ann. Chim, Phys. lvii. p. 300. 
§ Ann. Chem. Pharm. xxxiv. p. 147. 
|| Ber. Deutsch. chem. Ges. xx. ref. 66. 
q Ann. Chim. Phys. [5] xxviii. p. 67. 
** Ann. Chem. Pharm. c. p. 125. 
++ Ber. Deutsch. chem. Ges. iil. p. 412. 
