4-Amino-1-benzylpiperidine
[CAS# 50541-93-0]

Identification

• Classification: Organic raw materials >> Heterocyclic compound >> Piperidines
• Name: 4-Amino-1-benzylpiperidine
• Synonyms: 1-Benzylpiperidin-4-amine
• Molecular Formula: C₁₂H₁₈N₂
• Molecular Weight: 190.29
• CAS Registry Number: 50541-93-0
• EC Number: 256-620-9
• SMILES: C1CN(CCC1N)CC2=CC=CC=C2

Properties

• Density: 1.0±0.1 g/cm³ Calc.^*, 0.93 g/mL (Expl.)
• Boiling point: 281.2±33.0 °C 760 mmHg (Calc.)^*, 322.6 °C (Expl.)
• Flash point: 113.9±20.5 °C (Calc.)^*, 109 °C (Expl.)
• Solubility: water: insoluble (Expl.)
• Index of refraction: 1.561 (Calc.)^*, 1.543 (Expl.)

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H319-H335
• Safety Statements: P261-P264-P264+P265-P271-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335
Acute toxicity	Acute Tox.	4	H312
Skin corrosion	Skin Corr.	1B	H314
Acute toxicity	Acute Tox.	4	H302
Serious eye damage	Eye Dam.	1	H318

Discovery and Applications

4-Amino-1-benzylpiperidine is a substituted piperidine featuring a benzyl group attached to the nitrogen and an amino group at the 4-position of the ring. Its molecular formula is C₁₂H₁₈N₂, with a molecular weight of approximately 190.29 g/mol. At ambient temperature, the compound appears as a clear to slightly yellow liquid or an off-white powder, depending on the form.

This compound is primarily used as an intermediate in organic synthesis, especially in pharmaceutical and medicinal chemistry. Its structure enables multiple functional modifications: the benzyl group can be hydrogenated off or serve as a protecting group for the nitrogen, while the free amino group enables coupling or further substitution. These features make it valuable in the construction of bioactive molecules.

Reported uses include acting as a precursor in the synthesis of butyl 4-amino-1-piperidineacetate, an important intermediate for assembling complex amide-linked structures. It serves as a building block for various pharmaceutical classes, including selective kinase inhibitors, antiplasmodial agents, dual-activity cholinesterase and amyloid-β aggregation inhibitors, muscarinic receptor antagonists, and imaging agents targeting sigma receptors. It has also been incorporated into photostable near-infrared cyanine dyes and radiolabeled compounds for diagnostic use.

In drug design, modifications of the piperidine scaffold derived from this intermediate support diverse therapeutic targets, including overactive bladder, neurological disorders, inflammation, and cancer. The ability to selectively functionalize at the 4-amino position provides bespoke derivatization for achieving receptor subtype selectivity or optimizing drug-like properties.

The compound is available from chemical suppliers with high purity (≥98 % by HPLC), sometimes as the free base or salt forms. It is typically stored at 2–8 °C and handled under standard laboratory safety conditions. Safety data indicate the compound is a skin and eye irritant, with hazard classifications warranting lab coat, glove, and eye protection, as well as proper ventilation during handling. It has a flash point around 110 °C and a density close to 0.93 g/mL.

In summary, 4-Amino-1-benzylpiperidine is a versatile piperidine derivative used extensively as a synthetic building block for pharmaceuticals, agrochemicals, dye intermediates, and diagnostic agents. Its functional groups offer dual reactivity, enabling broad structural elaboration, while its chemical and physical stability support reliable utility in research and development.

References

2025. Multi-targeted benzylpiperidine-isatin hybrids: Design, synthesis, biological and in silico evaluation as monoamine oxidases and acetylcholinesterase inhibitors for neurodegenerative disease therapies. Journal of Computer-Aided Molecular Design, 39(2).
DOI: 10.1007/s10822-025-00588-2

2024. Design, synthesis, and evaluation of benzylpiperidine-derived hydrazones as dual inhibitors of monoamine oxidases and acetylcholinesterase. Medicinal Chemistry Research, 34(2).
DOI: 10.1007/s00044-024-03365-2

2023. Open science discovery of potent noncovalent SARS-CoV-2 main protease inhibitors. Science, 382(6671).
DOI: 10.1126/science.abo7201