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. Cinnamic acid is a precursor to the sweetener aspartame via enzyme-catalysed amination to give phenylalanine.

Cinnamic acids have been prepared in moderate to high yields by a new direct synthesis using aromatic aldehydes and aliphatic carboxylic acids, in the presence of boron tribromide as reagent, 4-dimethylaminopyridine (4-DMAP) and pyridine (Py) as bases and N-methyl-2-pyrolidinone (NMP) as solvent, at reflux

Cinnamic acid was synthesized using Perkin reaction by reacting 0.05 mole of benzaldehyde with 0.073 mole of acetic acid anhydride and 0.03 mole of sodium acetate as a catalyst in the Erlenmeyer flask and then the mixture was put in a sonicator for 60 minutes at 70 oC.

CINNAMIC ACID FOR SYNTHESIS