4Hydroxyphenylacetaldehyde

4-Hydroxyphenylacetaldehyde is an aromatic aldehyde with the formula C8H8O2. Its structure features a benzene ring with a para-hydroxy substituent and a two-carbon side chain ending in an aldehyde group, giving the common name 4-hydroxyphenylacetaldehyde.

Biological context and occurrence

In biological systems, 4-hydroxyphenylacetaldehyde commonly arises as an intermediate in the catabolism of phenylethylamines. It is produced by the oxidative deamination of tyramine (4-hydroxyphenethylamine) via monoamine oxidase, after which the aldehyde can be further oxidized to 4-hydroxyphenylacetic acid by aldehyde dehydrogenase. The compound can also appear transiently within various microbial and plant phenylpropanoid pathways as an intermediate in aromatic metabolism.

Chemical properties and reactivity

The molecule contains both a phenolic hydroxyl group and an aldehyde function, making it reactive toward oxidation, reduction, and nucleophilic addition. The aldehyde moiety enables typical carbonyl chemistry, while the phenolic OH can participate in hydrogen bonding and influence acidity and solubility. The compound is generally more soluble in organic solvents than in water, owing to its relatively nonpolar benzene core, though the phenolic group provides some polarity.

Applications and research context

4-Hydroxyphenylacetaldehyde is mainly encountered as a metabolic intermediate in studies of tyrosine/tyramine metabolism and related microbial and plant pathways. In synthetic chemistry, it can serve as a precursor or building block for the preparation of fragrances, dyes, or pharmaceutical intermediates after appropriate functional-group transformations.

Safety

As an aldehyde, it can be reactive and potentially irritating to skin, eyes, and the respiratory system. It should be handled in a well-ventilated area with appropriate protective equipment and stored away from oxidants.