Chemical Identity and Physical Properties

tert-Butyl 3-(aminomethyl)azetidine-1-carboxylate hydrochloride (Aladdin SKU T189892) is a four-membered nitrogen heterocycle featuring a tert-butoxycarbonyl (Boc) group on the ring nitrogen and a primary aminomethyl substituent at the C-3 position, isolated as the hydrochloride salt for enhanced stability and ease of handling.

The azetidine scaffold contributes significant three-dimensional character (high sp3 fraction) compared with planar aromatic heterocycles, a property increasingly sought in modern drug discovery to improve aqueous solubility, reduce promiscuous binding, and modulate metabolic stability. The exocyclic –CH₂NH₂ group (protonated as –CH₂NH₃⁺Cl^– in the salt form) provides a reactive handle for amide bond formation, reductive amination, sulfonamide formation, and urea/carbamate synthesis after liberation of the free base.

The Boc protecting group on the ring nitrogen is orthogonal to standard Fmoc/Cbz strategies and is cleanly removed under mild acidic conditions (e.g., 20–50% TFA in DCM, or 4 M HCl in dioxane) without affecting most common functional groups, enabling selective deprotection in multistep sequences.

Handling, Safety, and Storage Guidelines

Personal Protective Equipment (PPE): Handle with appropriate PPE including nitrile gloves, safety spectacles, and a laboratory coat. Operations generating dust or aerosols should be performed in a well-ventilated fume hood. As an amine-containing compound, the material may cause skin and eye irritation; avoid inhalation of dust.

Storage: Store the compound in a tightly sealed container in a cool (2–25 °C), dry environment protected from light and moisture. The hydrochloride salt form is generally more hygroscopic than the free base; minimise exposure to atmospheric humidity during weighing. Desiccants (silica gel or molecular sieves) are recommended for long-term storage.

Stability: The Boc group is susceptible to acid and elevated temperatures; avoid prolonged exposure to strongly acidic conditions or temperatures above 40 °C during storage. Solutions in common organic solvents (DMF, DMSO, DCM, MeOH) should be prepared freshly or stored under inert atmosphere.

Disposal: Dispose of waste material in accordance with local, national, and institutional regulations for amine-containing organic compounds. Do not pour down the drain without appropriate neutralisation and authorisation.

Note: Consult the Safety Data Sheet (SDS) for T189892 for comprehensive hazard information before use.

Synthetic Applications and Reaction Protocols

tert-Butyl 3-(aminomethyl)azetidine-1-carboxylate hydrochloride serves as a bifunctional building block in which the two nitrogen atoms can be addressed sequentially or orthogonally. Typical workflows are outlined below.

1. Free-base Liberation: Prior to coupling reactions, the hydrochloride salt is converted to the free base by treatment with an inorganic base (e.g., K₂CO₃, Na₂CO₃, or NaOH in aqueous/organic biphasic systems) or by passage through a basic ion-exchange resin. Alternatively, the salt can be used directly with excess base in situ (e.g., DIPEA, TEA) in polar aprotic solvents such as DMF or NMP.

2. Amide Bond Formation: The primary amine reacts with activated carboxylic acids (acid chlorides, NHS esters) or carboxylic acids activated with standard coupling reagents (HATU, HBTU, EDC/HOBt) in DMF or DCM, typically at 0 °C to room temperature, to furnish Boc-azetidine amide products in good yield.

3. Reductive Amination: The primary amine undergoes reductive amination with aldehydes and ketones using sodium cyanoborohydride (NaBH₃CN) or sodium triacetoxyborohydride (NaBH(OAc)₃) in MeOH or DCE at room temperature, enabling rapid introduction of diversity around the aminomethyl nitrogen.

4. Boc Deprotection: After construction of the desired motif on the exocyclic amine, the Boc group on the azetidine ring nitrogen is removed with TFA (20–50% in DCM, 0 °C to RT, 1–2 h) or HCl (4 M in dioxane), exposing the secondary azetidine amine for further elaboration such as acylation, sulfonylation, or alkylation.

5. Parallel and Automated Synthesis: The compound is suitable for parallel synthesis workflows and library generation on nanomole to millimole scale, and is compatible with standard liquid-handling and solid-phase extraction platforms.

Quality, Purity, and Analytical Verification

Aladdin Scientific supplies T189892 with a certificate of analysis (CoA) documenting identity and purity. Researchers should verify the following upon receipt:

• Identity: Confirm by ¹H NMR (characteristic azetidine ring protons, Boc singlet near δ 1.44 ppm in CDCl₃ or D₂O), and by HRMS or ESI-MS consistent with the molecular formula of the free base (C₉H₁₈N₂O₂) plus the HCl adduct.
• Purity: Assess by HPLC (reverse-phase C18 column, UV detection at 210–220 nm) or by quantitative NMR (qNMR). Typical research-grade material is ≥95% pure; confirm specification on the CoA.
• Water content: Determine by Karl Fischer titration if the application is moisture-sensitive, particularly given the hygroscopic nature of the HCl salt.
• Chloride content: Ion chromatography or argentometric titration can confirm stoichiometric incorporation of HCl where required for precise molarity calculations.

Retain the CoA and SDS for each lot received. If analytical data deviate from specification, contact Aladdin Scientific technical support before use.