3-Boc-aminopyrrolidin-2-one is a heterocyclic organic compound featuring a pyrrolidinone core structure with a tert-butoxycarbonyl (Boc)-protected amino group at the 3-position. This white to off-white solid is a versatile and crucial building block in medicinal chemistry. Its primary application is as a key intermediate in the synthesis of various pharmaceutical agents. The Boc-protected amine serves as a masked primary amine, allowing for selective deprotection under mild acidic conditions to introduce the amine functionality into target molecules. This scaffold is particularly valuable for constructing constrained peptidomimetics and for the development of protease inhibitors, kinase inhibitors, and other bioactive compounds where the pyrrolidinone ring can act as a rigid linker or a bioisostere. As a protected amino acid derivative, it is a fundamental synthetic precursor. Its well-defined reactivity makes it a staple in multi-step organic synthesis for drug discovery programs, enabling efficient access to complex molecular architectures.