4-Amino-3-nitrophenylboronic acid pinacol ester is an organoboron compound characterized by a phenyl ring substituted with an amino group, a nitro group, and a boronic acid pinacol ester moiety. The CAS number is 833486-94-5. The pinacol ester group serves as a protecting group for the boronic acid, enhancing its stability and handling properties compared to the free acid form. This compound is primarily utilized as a versatile building block in organic synthesis, particularly in Suzuki-Miyaura cross-coupling reactions. The protected boronic acid functionality allows for efficient palladium-catalyzed coupling with various aryl or vinyl halides to construct biaryl or styrene derivatives. The presence of both electron-donating (amino) and electron-withdrawing (nitro) substituents on the aromatic ring makes it a valuable intermediate for synthesizing complex molecules with specific electronic properties for research purposes. As a bifunctional synthon containing both a boronate ester and an amine, it finds application in the synthesis of pharmaceuticals, agrochemicals, and functional materials. The amine group can be further derivatized, offering additional points for structural diversification. Standard safety precautions for handling organic compounds and boronic acid derivatives should be observed.