CINNAMIC ACID, or Phenylacrylic Acid, C9H80 2 or C 6 H 5 CH: CH COOH, an acid found in the form of its benzyl ester in Peru and Tolu balsams, in storax and in some gumbenzoins.
It occurs naturally in some resins, especially in gum benzoin (from Styrax benzoin), in dragon's blood, and as a benzyl ester in Peru and Tolu balsams. It can be prepared by the oxidation of toluene, benzyl alcohol, benzaldehyde and cinnamic acid; by the oxidation of benzene with manganese dioxide and concentrated sulphuric acid in the cold (L.
In this group may be included the oleo-resins, such as copaiba, cubebs and Canada balsam; the gum-resins, such as asafetida, myrrh, ammoniacum and galbanum; and the true balsams, such as benzoin, storax, balsam of Tolu and balsam of Peru.
He began his experimental work in 1841 with investigations of oil of turpentine and tolu balsam, in the course of which he discovered toluene.