Step 1: Understanding the Concept:
Many organic compounds have traditional "common names" derived from their natural origins long before formal IUPAC nomenclature was established. "Oil of wintergreen" is a naturally occurring ester found in plants like wintergreen (\textit{Gaultheria procumbens}) and sweet birch. It is famous for its minty, cooling fragrance and its medicinal properties. Esters are organic compounds produced by the reaction between an alcohol and a carboxylic acid (esterification). In the case of oil of wintergreen, the molecule is the product of the esterification of salicylic acid (a phenolic acid) with methanol (a simple alcohol). This compound is widely used in the pharmaceutical industry as a topical analgesic and in the food industry as a flavoring agent.
Step 2: Detailed Explanation:
Let's analyze the chemical identity of each option to find the correct match:
(1) Methyl acetate: This is an ester formed from Acetic acid (\(CH_{3}COOH\)) and Methanol (\(CH_{3}OH\)). It is a colorless liquid with a fruity, glue-like smell. It is used primarily as a solvent and is not related to wintergreen.
(2) Methyl salicylate: This is the ester formed from Salicylic acid (\(2\)-hydroxybenzoic acid) and Methanol. Its structure consists of a benzene ring with a hydroxyl group (\(-OH\)) and a methyl ester group (\(-COOCH_{3}\)) at the ortho position. This molecule is the primary constituent of natural oil of wintergreen. When applied to the skin, it causes a sensation of warmth and helps relieve muscle and joint pain (acting as a rubefacient).
(3) Ethyl salicylate: This is the ester of Salicylic acid and Ethanol (\(C_{2}H_{5}OH\)). While it has a similar structure, it has a slightly different odor and physical properties. It is not the compound referred to as "oil of wintergreen."
(4) Salicylic acid: This is the parent acid. It is a white crystalline solid that is precursor to many drugs, including Aspirin. However, as an acid, it does not have the "oily" physical state or the specific aromatic profile of the wintergreen ester.
Industrial Note: Methyl salicylate is synthesized industrially by heating salicylic acid with methanol in the presence of a strong acid catalyst like sulfuric acid. This is a classic Fischer-Speier esterification.
Step 3: Comparison:
The correspondence between the trivial name "Oil of Wintergreen" and the chemical name "Methyl salicylate" is a standard fact in organic chemistry curricula. It is often taught alongside other salicylic acid derivatives like Aspirin (Acetylsalicylic acid) and Salol (Phenyl salicylate).
Step 4: Final Answer:
The chemical name for Oil of wintergreen is methyl salicylate.
Therefore, option (2) is correct.