Wintergreen oil can be obtained by collecting the branches and leaves of Ilex cornuta (commonly known as holly) from the Ericaceae family and extracting it using steam distillation. The holly branches and leaves are chopped, soaked, and then steam distilled to separate the oil from the water. The oil is then fractionated under reduced pressure, and the middle fraction free of water and acid is collected.
Salicylic acid is added to a reaction vessel, along with excess methanol. While stirring, sulfuric acid (a catalyst) is added, and the reaction is heated. After the reaction is complete, the mixture is washed with water until neutral. Distillation is then performed; first, methanol and residual water are distilled off under normal pressure, and then the fraction is collected under reduced pressure.
Methyl salicylate can be isolated from the natural essential oil using fractional distillation.
