8/10/2019 Synthesis of Methyl Salicylate.docx

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Synthesis of Methyl SalicylateSilverio, A. Soriano, R. Tan, J. Tequillo H. Tolentino M.

University of Santo Tomas Faculty of Pharmacy

Abstract:Performed in this experiment was synthesis of Methyl salicylate from aspirin. During the said activity, the

commercially available aspirin was compounded to be used as the source of the acetylsalicylic acid, which is much

easier to come by than salicylic acid, and performed esterification, where a condensation reaction between analcohol and an acid, typically in the presence of a strong acid catalyst, such as sulfuric acid. Water bath of 5-10

minutes with maintained temperature of 70C was done; strong minty odor of the ester was observed and indicated

the complete synthesis of methyl salicylate, also known as Oil of Wintergreen

I. BackgroundEsters are a class of organic compounds. An ester compromises an organic or inorganic acid inwhich one or more hydroxy (OH) groups have been replaced by and alkoxy(O-alkyl) group. Forexample, the simplest ester, methyl formate (CHO-OCH3), is made up of formic acid (CHO-OH) inwhich the hydroxyl group has been replaced by a methoxy group (OCH 3).Similarly, ethyl acetate (CH3CO-OCH2CH3) is made up of acetic acid (CH3CO-OH) in which the

hydroxy group has been replaced by an ethoxy group (-OCH2CH3) Although esters can be producedby many mechanisms, the most commonly used method is called esterification, which is acondensation reaction between an alcohol and an acid, typically in the presence of a strong acidcatalyst, such as sulfuric acid. For example, ethyl acetate can be produced by reacting ethanol (ethylalcohol) with acetic acid and isopropyl butyrate by reacting isopropanol (isopropyl alcohol) with butyricacid. Esters were traditionally named by combining the name of the alcohol with the root name of theacid and adding ate as a suffix. Traditional names are still widely used by most chemists,particularly for the simple esters. The IUPAC naming system uses the systematic names for thealcohol and root name of the acid, followed by oate. For example, the traditional name n -amylacetate (n-amyl alcohol with acetic acid) is represented in IUPAC nomenclature as 1-pentyl ethanoate(1-pentyl alcohol, the systematic name for n-amyl alcohol, with ethanoic acid, the systematic name foracetic acid). Esters typically have strong, often pleasant, scents and tastes, so many esters are usedas flavorings and perfume agents, either individually or in combination For example, the scent andtaste of strawberries is due to the presence of (among others) methyl cinnamate, ethyl butyrate, ethylcaproate, isobutyl acetate, and benzyl acetate.

II. Materials and Method

a. ApparatusHard Glass Test Tubes10mL Graduated CylinderDropping pipetteStirring rodThermometer

b. ReagentsSalicylic acidMethyl alcoholSulphuric acid

c. Method1. Salicylic acid was weighed 1 gram then was transferred to a hard glass test tube2. 5mL of methyl alcohol was added3. 3 drops of Concentrated Sulfuric acid was carefully added in the solution

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4. The Salicylic acid was stirred until completely dissolved.5. Test tube was placed on a water bath with maintained temperature of 70C for 15minutes6. The odor of the solution was recorded.

III. Results

The solution has an odor of strong mint odor.

IV. Conclusion

The reaction of Salicylic acid to Methyl Alcohol is shown in figure number 1.

Figure 1.Reaction of Salicylic acid to Methyl Alcohol

This reaction can give therapeutic effects that treat minor aches and pains of themuscles/joints (e.g.,arthritis,backache, sprains). Menthol and methyl salicylate areknown as counterirritants. They work by causing theskin to feel cool and then warm.These feelings on the skin distract you from feeling the aches/pains deeper in yourmuscles, joints, and tendons.

V. Reference

[1] Thompson, R.B. (2008). Illustrated guide to home chemistry experiments. Beijing: O'Reilly

[2] Retrieved from: Web MD, 201. http://www.webmd.com/drugs/drug-18536-methyl+salicylate-

menthol+top.aspx?drugid=18536&drugname=methyl+salicylate-menthol+top

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