Phenylacetaldehyde

Phenylacetaldehyde, also known as 2-phenylethanal, is an aromatic aldehyde with the molecular formula C8H8O. It is commonly encountered as a colorless liquid with a pronounced floral odor and is used in perfumery, flavorings, and as an intermediate in organic synthesis. It can occur in trace amounts in some essential oils and is produced by plants during fragrance emission.

In industry and research, phenylacetaldehyde is typically prepared by oxidation of 2-phenylethanol (phenethyl alcohol) using mild oxidants or selective catalytic oxidation. It is also accessible through other synthetic routes that convert the corresponding alcohol or related precursors. As a reactive aldehyde, it participates in a variety of common aldehyde reactions, including oxidation to phenylacetic acid, reduction to 2-phenylethanol, and condensation or imine formation with amines. These properties make it a versatile building block in the synthesis of fragrances, flavor compounds, and pharmaceutical or agricultural intermediates.

Safety and handling considerations include the fact that phenylacetaldehyde is an irritant and its vapors can affect the eyes, skin, and respiratory tract. It is flammable and should be stored away from heat, ignition sources, and oxidizers. Appropriate protective equipment, such as gloves and goggles, should be used when handling concentrated samples. As with many aldehydes, careful control of reaction conditions is important to minimize undesired side reactions and odors during use.