Methyl Salicylate from Salicylic Acid
I used the ~43 grams of Salicylic Acid made in a previous post to synthesize methyl salicylate. Methyl salicylate is the ester that gives wintergreen its distinct flavor and odor. The process is known as a fischer esterification. The procedure is simple, and consists of dissolving the salicylic acid in an excess of anhydrous methanol, and then adding 40ml of concentrated sulfuric acid as a catalyst and refluxing for about two hours. After the reflux, around 50% of the methanol is distilled until the oil methyl salicylate precipitates. The mixture is poured into a separatory funnel and the oil layer is isolated. The oil is then washed with saturated sodium bicarbonate solution twice. The oil, cloudy with methanol and water is then dried using calcium chloride. The oil is totally clear and has a very pleasant refractive index. It has a slight yellow color due to dissolved sulfuric acid and contaminants. Depending on its eventual application I may or may not neutralize the acid. It is no...