pTolualdehyde

p-Tolualdehyde, also known as 4-methylbenzaldehyde, is an aromatic aldehyde with the chemical formula C8H8O. It consists of a benzene ring bearing a formyl group (CHO) para to a methyl substituent. It is typically a colorless to pale yellow liquid that is sparingly soluble in water and soluble in many organic solvents, with an odor characteristic of benzaldehyde compounds.

Commercially, p-tolualdehyde is mainly produced by selective oxidation of p-tolylmethanol using mild oxidants, or by other catalytic oxidation routes from substituted benzenes such as p-xylene. The synthesis aims to preserve the para methyl and formyl substituents on the aromatic ring without over-oxidation to the corresponding acids.

As a benzaldehyde derivative, p-tolualdehyde is a useful building block in organic synthesis. It serves as an intermediate in the production of dyes, fragrances, and pharmaceutical compounds. It undergoes typical aldehyde reactions, including oxidation to p-toluic acid, reduction to p-tolylmethanol, and condensation reactions to form imines or related derivatives, enabling further functional group transformations on the aromatic core.

Safety handling typically notes irritant and potentially harmful effects on skin, eyes, and the respiratory system. It should be used with appropriate personal protective equipment, in well-ventilated areas, and stored in tightly closed containers away from incompatibles.