Chemistry is an interesting subject that includes the study of basic components like atoms, molecules, ions, electrons also involve various process and reactions under different conditions. Many great scientist and chemists have contributed to the development of the field. There are many scientists who have been awarded Nobel prize for their outstanding contributions. Preparations of each and every chemical compound differ and the process involved will be unique. Now let us try to understand how cinnamic acid is prepared along with α,β -unsaturated aromatic acid. study in australia
Perkin Reaction is a well know organic condensation chemical reaction that was developed by William Henry Perkin the great English chemist to produce cinnamic acid. Perkin Reaction produces α,β – unsaturated aromatic acid and is a chemical reaction that takes place between the aliphatic acid anhydride, aromatic aldehydes, and the alkali salt of the acid. Here the alkali salt acts as a base catalyst.
Perkin reaction is as generalized and is given below. It clearly shows how the Perkin reaction produces an alpha, beta-unsaturated aromatic acid through the aldol condensation of an aromatic aldehyde, alkali salt of the acid and acid anhydride. This alkali salt acts as a base catalyst. Other bases can be used instead of the alkali salt of the acid in the Perkin reaction.
Process of Perkin Reaction
the anhydride produces the carbanion in the presence of the base. The resultant carbanion attacks the carbonyl carbon of the aldehyde producing an intermediate. The abstraction of a proton from the active methyl group of the intermediate by the given base and the subsequent removal of the hydroxyl group yields unsaturated anhydride.
This product is now hydrolyzed to finally give α,β -unsaturated acid. The representation of the Perkin reaction mechanism is given below.
Activation energy is defined as the energy that is essential for a nuclear or chemical system with potential reactants to result in a nuclear reaction, chemical reaction, or various other physical aspects. Activation energy is represented as Ea and is measured in Joules (J). This concept was introduced by a Swedish scientist Svante Arrhenius.
Activation energy varies from one reaction to another. Activation energy is dependent on various factors like:
Arrhenius equation provides the quantitative basis of the relationship between the rate at which a reaction proceeds and the activation energy. The activation energy can be determined through the equation:
Activation energies are determined from experimental rate constants or diffusion coefficients that are measured at different temperatures.