Maminophenyl

Maminophenyl, or meta-aminophenyl, refers to a phenyl substituent bearing an amino group at the meta (3-) position relative to another substituent on the ring. It is not a standalone compound but a structural fragment used in the naming of larger molecules. The term is common in organic synthesis and is often written as m-aminophenyl.

In practice, the meta-aminophenyl group appears in dyes, pharmaceutical intermediates, agrochemicals, and polymer chemistry as a versatile building block. It can serve as a handle for further transformations, such as diazotization to form diazonium salts for azo coupling, or conversion to amides, sulfonamides, and other derivatives. Typical routes to introduce a meta-aminophenyl moiety include reduction of 3-nitroaniline derivatives or cross-coupling strategies starting from meta-substituted aryl precursors with the amino functionality installed earlier.

Properties and reactivity: The amino group on an aminophenyl ring is basic, with behavior similar to that of aniline, though the exact pKa of the conjugate acid can vary with substituents on the ring. The meta orientation can influence electronic distribution and steric effects, affecting reactivity in electrophilic aromatic substitution and in cross-coupling or coupling-partner reactions.

Related terms: Other positional isomers of aminophenyl include the ortho (2-aminophenyl) and para (4-aminophenyl) groups. These isomers differ in directing effects, reactivity, and physical properties within a given molecule.