Aldehydes
DETAIL
It is a colorless liquid with a characteristic almond-like odor. The primary component of bitter almond oil, benzaldehyde can be extracted from a number of other natural sources. Synthetic benzaldehyde is the flavoring agent in imitation almond extract, which is used to flavor cakes and other baked goods.
Uses
Benzaldehyde is commonly employed to confer almond flavor to foods and scented products. It is sometimes used in cosmetics products.
In industrial settings, benzaldehyde is used chiefly as a precursor to other organic compounds, ranging from pharmaceuticals to plastic additives. The aniline dye malachite green is prepared from benzaldehyde and dimethylaniline. Benzaldehyde is also a precursor to certain acridine dyes. Via aldol condensations, benzaldehyde is converted into derivatives of cinnamaldehyde and styrene. The synthesis of mandelic acid starts with the addition of hydrocyanic acid to benzaldehyde:
mandelic acid synthesis
The resulting cyanohydrin is hydrolysed to mandelic acid. (The scheme above depicts only one of the two formed enantiomers).
Niche uses
Benzaldehyde is used as a bee repellent. A small amount of benzaldehyde solution is placed on a fume board near the honeycombs. The bees then move away from the honey combs to avoid the fumes. The beekeeper can then remove the honey frames from the bee hive with less risk to both bees and beekeeper.
Additionally, benzaldehyde is also used as a flavour chemical in JUUL e-cigarette pods, particularly the "Cool Mint", "Cool Cucumber", and "Fruit Medley" varieties. The concentration is relatively low, at ~1 μg/mL.