An important characteristic in the mechanism of the reaction is the formation of a tetrahedral intermediate which is the result of the alcohol present attacking the 2-phenylacetic acid together with the subsequent loss of a proton. This reaction is called the fischer esterification. It is a special type of an esterification reaction by which a carboxylic acid and alcohol are refluxed and reacted forming an ester in the presence of a catalyst which is an acid. Along with the formation of ester, a water molecules would be eliminated during the course of the reaction. This reaction is said to be reversible.