(9H-Fluoren-9-yl)methyl (6-aminohexyl)carbamate hydrochloride is the Fmoc-protected form of 6-aminohexan-1-amine, serving as a key building block and linker in advanced organic and biochemical synthesis. The Fmoc group selectively protects one primary amine, leaving the other available for coupling reactions. It is extensively used in solid-phase peptide synthesis (SPPS) to incorporate aminohexyl spacers into peptides, enabling C-terminal modifications or bioconjugations. After assembly, the Fmoc is readily removed with mild acid (e.g., piperidine in DMF) to expose the amine for further functionalization. This compound is also vital in oligonucleotide synthesis for attaching amino linkers to DNA/RNA probes, facilitating immobilization on surfaces, labeling, or conjugation to proteins/drugs in diagnostic tools, microarrays, and therapeutic development. Its orthogonal protection strategy enhances control, yield, and versatility in constructing complex biomolecules for pharmaceutical and biotech research.