Synthesis of Salicylic Acid from Oil of Wintergreen

Background

Methyl salicylate and salicylic acid are naturally occurring compounds with medicinal properties. On top of that, the procedure that you will apply here, saponification, is a well-known method for converting natural fats into soap. So is there some practical  connection between making medicines and making soap? None that I know of.

But, let’s think about this in the way organic chemists do. Fats are esters of carboxylic acids, and soaps are the sodium salts of the corresponding carboxylic acids. Is there something special about fats that make these esters susceptible to saponification? If we answer in the negative (“No, I don’t think there is anything special about esters from fats”), then a natural way to test our hypothesis is to attempt the saponification of an ester that does not come from fats. That is exactly what we will do here.

The rest of this page looks more closely at saponification from the standpoint of functional groups (carboxylic acids, esters, etc.), and chemical reaction mechanisms, but first, I can’t resist sharing some stories about the medicinal uses and history of these remarkable compounds.

Salicylic acid

Aspirin

Methyl salicylate

Saponification

Continue to Procedure…