Methyl salicylate, odor

Concentrated sulfuric acid and methanol Dilute hydrochloric acid Silver nitrate 0.5 g of sample + 3 ml of reagent + heat evolves methyl salicylate (odor of wintergreen) Crystalline precipitate of salicylic acid Heavy crystalline precipitate of silver salicylate (which is soluble in boiling water and recrystallizes upon cooling)... 

Remove the watch glass and waft the methyl salicylate odor toward your nose. Record your observations. 

See also methacrylate odor absorbers, 169 oil drilling mud, 146 oil of wintergreen, 167, 186. See also methyl salicylate... 

Hydroxybenzoic acid is obtained as white crystals, fine needles, or fluffy white crystalline powder. It is stable in air and may discolor gradually in sunlight. The synthetic form is white and odorless. When prepared from natural methyl salicylate, it may have a light yellow or pink tint and a faint, wintergreen-like odor. w-Hydroxybenzoic acid crystallizes from water in the form of white needles and from alcohol as platelets or rhombic prisms. -Hydroxybenzoic acid crystallizes in the form of monoclinic prisms. Various physical properties of hydroxybenzoic acids are listed in Tables 1—4. 

Fig. 5.1. A sample of floral scent compounds. (1) Substituted methyl esters of benzoic acid. The ester smells unpleasantly sweet when R = H (methyl benzoate), of wintergreen when R = OH (methyl salicylate), and of concord grape when R = NH2 (methyl anthranylate). Odorants with unusual origins and biological functions include the homoterpene 4,8-dimethyl-1,3,7-nonatriene (2) and the wet-earth compound geosmin (3). Some ubiquitous fragrance compounds are ben-zaldehyde (4), benzyl alcohol (5), indole (6), (S)-linalool (7), ( )-/ -ocimene (8), and of-farnesene (9).

Fig. 5.2. Gas chromatography (GC) and electroantennography (EAG) analysis of male Manduca sexta antennal responses to floral volatiles from the night blooming cactus Peniocereus greggii. The upper trace is a flame ionization detection (FID) chromatogram of floral headspace odors separated on a carbowax GC column, while the lower trace is a simultaneous recording of summed antennal action potentials elicited by individual compounds as they elute. The largest absolute responses followed methyl benzoate, methyl salicylate, and benzyl alcohol (peaks 3-5, respectively). Note the poor responses (circled) to benzaldehyde and benzyl benzoate (peaks 2, 6) and the disproportionately higher responses (bold arrows) to methyl salicylate and benzyl salicylate (peak 7) relative to their peak areas. Peak 1 is the internal standard (toluene) remaining unnumbered peaks are ambient contaminants.

Essential oils are obtained from fruits and dowers (61,62). Volatile esters of short- and medium-chain carboxylic acids or aromatic carboxylic acids with short- and medium-chain alcohols are primary constituents of essential oils, eg, ethyl acetate in wines, brandy, and in fruits such as pineapple benzyl acetate in jasmine and gardenia methyl salicylate in oils of wintergreen and sweet birch. Most of these naturally occurring esters in essential oils have pleasant odors, and either they or their synthetic counterparts are used in the confectionery, beverage, perfume, cosmetic, and soap industries (see Oils,... 

Properties Colorless liquid faint odor of methyl salicylate. D 1.127-1.130, refr index 1.523, bp 231-234C. Soluble in ether and alcohol slightly soluble in water. Combustible. 

Tests for Methyl Alcohol.—(a) Methyl salicylate.—Mix together in a test-tube about 0.2 gram of salicylic acid, 1 cc. of concentrated sulphuric acid, and 1 cc. of methyl alcohol, and warm gently. Note and describe the odor. The compound formed is the methyl ester of a salicylic acid, HO.C6H4.COOCH3. 

When brought together under the proper conditions, an organic acid and an alcohol will react to form an ester. Esters are generally volatile compoimds having distinctive odors. In this MiniLab, you will combine methanol and salicylic acid to produce the ester, methyl salicylate. 

What famdiar odor is caused by methyl salicylate ... 

Clear, very refractive liquid pleasant odor resembling that of methyl salicylate. Becomes yellowish-brown on long exposure to air and light, dj 1.131. bp 231-234". mp +1. ng> 1.5226. Slightly sol jn water miscible with ale. ether. Protect from light. 

Sweat and Cheese descriptors overlap similar to the IR-generated odor maps. Minty smelling Methyl salicylate and Menthol produced distinct odor maps. 

Plastic application materials such as cables are destroyed by animals and especially by rodents. Therefore, additives may be incorporated to eliminate potential damage to these materials. Additives of choice to repel rodents are substances with a bitter taste, for example, denatonium benzoate, with a spicy taste (capsaicin, hot pepper), and/or with an unpleasant odor for animals (Fig. 11.25). Other substances repel birds, for example, natural oils or methyl salicylate [69]. 

In the early days of chemical science, molecular structures were unknown for substances such as benzaldehyde (from almonds) and methyl salicylate (from oil of wintergreen). These compounds have distinctive aromas, so they came to be called aromatic." As chemistry developed, it was recognized that many of these aromatic compoimds contain a benzene ring. In time the term aromatic came to mean a certain kind of structure and not a distinctive odor. 

In other instances, the parameters that determine pollination are complex. Many of these orchids attract only the male bee. When a flower is placed in an opaque container, the bees still find it, indicating that the bees use odor and not vision to locate the flowers. Even when the flower was removed, the bees continued to be attracted to the container. Most of the orchid species produce a combination of 7-10 compounds. Among these are fi -carvone (48), 1,8-cineole (10), eugenol, bomyl acetate (77), anethole, geraniol (4), methyl cinnamate, methyl salicylate, myrcene (17), vanillin, and indole. In pure form, 1,8-cineole, methyl salicylate, eugenol, methyl cinnamate, bomyl acetate, a-phellandrene (79), myrcene (17), piperonal, indole, vanillin, and benzyl acetate serve as attractants. Neither a- or P-pinene nor oci-mene (47) are attractive to the bees tested. Combinations of these compounds (in proportions similar to those found in various orchid species) lead to greater specificity of attraction. For example, when a-pinene (14) is added to a mixture of 1,8-cineole (10) and benzyl acetate in the proportions found in the orchid Stanhopea tricornis, fewer bees of two species are attracted than when a mixture of only 1,8-cineole... 

Methyl 2-hydroxybenzoate (methyl salicylate) has the odor of oil of wintergreen.This ester is prepared by the Fischer esterification of 2-hydroxybenzoic acid (salicylic acid) with methanol. Draw a structural formula of methyl 2-hydroxybenzoate. 

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