What Is the Mechanism for the Perkin Reaction?

The mechanism of the Perkin reaction follows 11 steps as described by Name-Reaction.com. Several eliminations and additions occur during the reaction, culminating with an acid work-up that results in the formation of an ?,?-unsaturated carboxylic acid, commonly called cinnamic acid.

The Perkin reaction was developed by William Henry Perkin and published in the year 1868. The mechanism describes the combination of an acid anhydride and an aromatic aldehyde through aldol condensation, using an alkali salt as the base catalyst, although other bases can be used instead. Additionally, other versions of the reaction may include decarboxylation without an acetic group transfer. The reaction's regiochemistry, or relative position of the aromatic ring and carbolyxic acid in the final result, can be either Z or E.

The result of the Perkin reaction, cinnamic acid, is an important element of the modern perfume industry. Dye manufacturers also use it in the synthesis of indigo dye, and pharmaceutical companies use cinnamic acid in the creation of certain drugs. Historians and chemists celebrate William Henry Perkin for his advancements in organic chemistry, particularly in the field of perfume and dye synthesis. He is most famous for his accidental discovery of mauveine, the first aniline dye, in 1856.