3-Aminoisoxazole: Properties, Uses & Handling FAQs

3-Aminoisoxazole is a five-membered nitrogen- and oxygen-containing heterocyclic compound bearing a primary amino group at the 3-position, widely used as a versatile building block in medicinal chemistry, agrochemical research, and the synthesis of complex heterocyclic frameworks.

CAS Number

1750-42-1

Molecular Formula

C₃H₄N₂O

Molecular Weight

84.08 g/mol

Appearance

White to off-white crystalline solid

Functional Groups

Primary amine (–NH₂) on an isoxazole ring

Key Application

Heterocyclic building block for drug discovery and agrochemical synthesis

SKU (Aladdin)

A124591

What Is 3-Aminoisoxazole?

3-Aminoisoxazole (CAS 1750-42-1) is a heteroaromatic compound belonging to the isoxazole family. Its core structure consists of a five-membered aromatic ring containing one nitrogen atom and one oxygen atom, with a primary amino (–NH₂) substituent at the 3-position. The combination of the electron-deficient isoxazole ring and the nucleophilic amine group makes this molecule a highly reactive and versatile intermediate in organic synthesis.

The isoxazole ring system is found in numerous biologically active natural products and pharmaceuticals, which drives sustained research interest in aminoisoxazole derivatives. The 3-amino regioisomer is particularly valued because the amino group can participate in condensation, acylation, sulfonylation, and cyclization reactions, enabling rapid assembly of structurally diverse libraries.

What Are the Key Chemical Properties of 3-Aminoisoxazole?

3-Aminoisoxazole possesses several important physicochemical properties relevant to laboratory handling and synthetic planning:

• Molecular formula: C₃H₄N₂O; molecular weight 84.08 g/mol.
• Aromaticity: The isoxazole ring is aromatic (6 π electrons), conferring planar geometry and relative thermal stability compared with non-aromatic analogues.
• Basicity: The exocyclic NH₂ group is weakly basic. The ring nitrogen (N-2) is also basic, though less so than typical aliphatic amines due to delocalization of the lone pair into the aromatic system.
• Solubility: Generally soluble in polar organic solvents such as methanol, ethanol, DMSO, and DMF; limited solubility in non-polar solvents such as hexane.
• Reactivity: The amino group undergoes standard amine chemistry including amide bond formation, reductive amination, diazotization, and heterocycle-forming condensations with 1,3-dicarbonyl equivalents.

Researchers should note that, like other primary aromatic-adjacent amines, 3-Aminoisoxazole may be sensitive to oxidation and prolonged exposure to light or moisture; proper storage is therefore essential.

What Are the Main Applications of 3-Aminoisoxazole in Research?

3-Aminoisoxazole is primarily employed as a synthetic building block and intermediate across several research domains:

1. Medicinal Chemistry & Drug Discovery: The aminoisoxazole scaffold appears in inhibitors targeting kinases, phosphodiesterases, and other enzymes. The amino group serves as a handle for elaboration via amide coupling, urea/thiourea formation, and Schiff base condensation, allowing rapid generation of focused libraries for structure–activity relationship (SAR) studies.
2. Agrochemical Research: Isoxazole-containing structures are present in several commercial herbicides and fungicides. 3-Aminoisoxazole acts as a precursor for the preparation of novel crop-protection agents.
3. Heterocycle Synthesis: The bifunctional nature of 3-Aminoisoxazole (aromatic NH and ring heteroatoms) makes it ideal for constructing fused bicyclic and polycyclic heterocyclic systems such as isoxazolo[3,4-d]pyrimidines and related scaffolds via cyclocondensation reactions.
4. Fluorescent Probe Development: Amino-substituted heterocycles are increasingly explored as fluorophore components or as precursors to fluorescent dyes used in bioimaging.

Researchers in combinatorial chemistry frequently incorporate 3-Aminoisoxazole into parallel synthesis workflows due to its commercial availability, moderate cost, and reliable reactivity.

How Should 3-Aminoisoxazole Be Stored and Handled Safely?

Storage recommendations: Store 3-Aminoisoxazole in a tightly sealed container, in a cool, dry, and well-ventilated location away from direct light, heat, and moisture. Refrigeration at 2–8 °C is typically advised to maintain long-term stability. Keep away from strong oxidizing agents, strong acids, and strong bases.

Personal protective equipment (PPE): Wear appropriate laboratory PPE including nitrile gloves, safety goggles, and a laboratory coat when handling this compound. Work in a fume hood or well-ventilated area to minimize inhalation of dust or vapors.

Disposal: Dispose of waste material in accordance with local, regional, and national environmental regulations. Do not pour down the drain without consulting your institution's chemical waste disposal guidelines.

First aid: In case of skin or eye contact, flush immediately with large amounts of water and seek medical attention if irritation persists. Consult the Safety Data Sheet (SDS) provided by Aladdin Scientific for complete hazard information before use.

Note: Specific GHS hazard classifications and precautionary statements should be confirmed from the official Aladdin Scientific SDS for product A124591.

How to Order 3-Aminoisoxazole from Aladdin Scientific

3-Aminoisoxazole is available from Aladdin Scientific under SKU A124591. To place an order:

1. Visit the Aladdin Scientific website and search for 3-Aminoisoxazole or the SKU A124591.
2. Select the desired quantity and packaging format, then add to your cart.
3. Proceed through checkout, selecting your preferred payment method (purchase order, credit card, or other supported options).
4. For bulk quantities, custom packaging, or institutional pricing inquiries, contact Aladdin Scientific's sales team directly via the website's inquiry form or customer service email.

Orders are processed and shipped according to Aladdin Scientific's standard shipping and delivery policies. Refer to the product page for current stock availability, pricing, and delivery lead times. A Certificate of Analysis (CoA) and Safety Data Sheet (SDS) are available for download on the product page.

Frequently asked questions

What is the CAS number of 3-Aminoisoxazole?

The CAS registry number for 3-Aminoisoxazole is 1750-42-1. You can use this number to search for the compound in chemical databases and to confirm product identity when ordering from Aladdin Scientific (SKU A124591).

Is 3-Aminoisoxazole suitable for use as a building block in drug discovery?

Yes. 3-Aminoisoxazole is widely used in medicinal chemistry as a building block for constructing biologically active heterocyclic compounds. The primary amino group at the 3-position allows diverse derivatization through amide coupling, urea formation, sulfonylation, and condensation reactions, making it ideal for SAR library synthesis. Researchers should verify suitability for specific biological targets based on their own experimental data.

What solvents can be used to dissolve 3-Aminoisoxazole?

3-Aminoisoxazole is generally soluble in polar organic solvents including methanol, ethanol, DMSO, and DMF. It has limited solubility in non-polar solvents such as hexane or diethyl ether. For biological assays, stock solutions are commonly prepared in DMSO. Always verify solubility under your specific experimental conditions.

What storage conditions are recommended for 3-Aminoisoxazole?

It is recommended to store 3-Aminoisoxazole in a tightly sealed container at 2–8 °C, protected from light, moisture, and heat. Keeping the compound under inert atmosphere (e.g., nitrogen or argon) can further prevent degradation due to oxidation or moisture uptake during long-term storage.

Does Aladdin Scientific provide a Certificate of Analysis for 3-Aminoisoxazole?

Yes. Aladdin Scientific provides a Certificate of Analysis (CoA) for product A124591, which includes purity data and analytical test results for the specific batch. The CoA and Safety Data Sheet (SDS) are available for download on the product page of the Aladdin Scientific website.

Can 3-Aminoisoxazole be used in cyclocondensation reactions to build fused heterocycles?

Yes. The bifunctional nature of 3-Aminoisoxazole — combining a nucleophilic exocyclic amine with the heteroatoms of the isoxazole ring — makes it an excellent substrate for cyclocondensation reactions. It has been employed in the synthesis of fused bicyclic systems such as isoxazolo-pyrimidines and isoxazolo-triazines. Specific reaction conditions will depend on the electrophilic partner and target scaffold.

References

1. Joule, J. A.; Mills, K. Heterocyclic Chemistry, 5th ed.; Wiley-Blackwell: Oxford, 2010. General reference for isoxazole chemistry and reactivity.
2. Aladdin Scientific product page for 3-Aminoisoxazole, SKU A124591. Certificate of Analysis and Safety Data Sheet available on request.
3. Stanovnik, B.; Svete, J. Synthesis of Heterocycles from Isoxazole Derivatives. Chem. Rev. 2004, 104, 2433–2480. General reference on isoxazole-based heterocycle synthesis. doi:10.1021/cr0200827

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