pnitroaniline

p-nitroaniline, also known as 4-nitroaniline, is an organic compound classified as an aromatic amine and a nitroarene. Its formula is C6H6N2O2, and it consists of a benzene ring bearing a nitro group (NO2) para to an amino group (NH2). It typically appears as pale yellow crystalline material and is soluble in various organic solvents.

Production of p-nitroaniline generally involves the nitration of aniline under strongly acidic conditions. The amino group directs electrophilic substitution to the para position, yielding a mixture of para- and ortho-nitroaniline isomers, from which the para isomer is separated and purified for commercial use.

Applications and reactions: p-Nitroaniline is a versatile intermediate in the synthesis of azo dyes and related pigments. The nitro group can be reduced to afford p-phenylenediamine, a key species in dye chemistry and polymer applications. The amino group can be diazotized to form diazonium salts, which participate in azo-coupling reactions with phenols or amines to produce numerous azo dyes. The compound can also undergo further ring functionalization under appropriate conditions.

Safety: p-Nitroaniline is toxic and can be irritating to skin, eyes, and the respiratory tract. It should be handled in a well-ventilated area with appropriate personal protective equipment, and stored away from reducing agents and incompatible materials. Disposal should follow applicable chemical waste regulations.