4-Chloropyridin-3-ol: Handling, Storage & Lab Protocol

4-Chloropyridin-3-ol is a halogenated hydroxypyridine building block widely employed in medicinal chemistry and synthetic research, requiring careful handling and controlled storage to maintain reagent integrity.

CAS Number

17368-12-6

Molecular Formula

C₅H₄ClNO

Molecular Weight

129.54 g/mol

Appearance

White to off-white crystalline solid

Recommended Storage

Cool, dry place; away from light and moisture

SKU

C128912

Safety & Personal Protective Equipment

Before working with 4-Chloropyridin-3-ol, consult the Safety Data Sheet (SDS) supplied with the product. Wear appropriate personal protective equipment (PPE) including nitrile gloves, laboratory coat, and safety goggles at all times. Work in a well-ventilated area or under a fume hood to minimize inhalation exposure to dust or vapors.

Avoid contact with skin, eyes, and clothing. In the event of skin contact, wash thoroughly with soap and water for at least 15 minutes. In the event of eye contact, flush immediately with copious amounts of water and seek medical attention. Do not ingest. Keep away from ignition sources, strong oxidizers, and strong bases.

Dispose of waste material in accordance with local, regional, and national environmental regulations.

Storage Conditions

Store 4-Chloropyridin-3-ol in a tightly sealed container in a cool, dry, and well-ventilated location, away from direct light and moisture. The recommended storage temperature is ambient (15–25 °C) or as specified on the product label. Prolonged exposure to moisture or elevated temperatures may lead to degradation of the compound.

Upon receipt, inspect the container for integrity and confirm the appearance matches the specification (white to off-white crystalline solid). If any discoloration or clumping is observed, contact Aladdin Scientific technical support before use. Re-seal the container promptly after each use under an inert atmosphere (e.g., nitrogen or argon) if hygroscopicity is suspected.

Solubility & Solution Preparation

4-Chloropyridin-3-ol is a polar heterocyclic compound. It is generally soluble in polar aprotic solvents such as dimethyl sulfoxide (DMSO) and dimethylformamide (DMF), and in polar protic solvents such as methanol and ethanol. Solubility in water may be limited; aqueous solutions may require pH adjustment or co-solvent addition.

To prepare a stock solution, weigh the required amount of solid on an analytical balance and dissolve in the chosen solvent with gentle agitation or brief sonication if necessary. For applications requiring aqueous formulations, prepare a concentrated stock in DMSO first and dilute with the aqueous buffer to the desired final concentration, keeping the DMSO content below 1% v/v where possible to avoid biological assay interference.

Verify complete dissolution visually before use. Filter through a 0.2 µm syringe filter for sterile applications.

Typical Laboratory Applications

4-Chloropyridin-3-ol serves as a versatile building block in synthetic and medicinal chemistry. The compound contains two functional handles: a nucleophilic hydroxyl group at the 3-position and an electrophilic chloro substituent at the 4-position, allowing selective functionalization under appropriate conditions.

Common transformations include nucleophilic aromatic substitution (SNAr) at the C-4 position using amines, thiols, or alkoxides to install diverse heteroatom substituents. The phenolic hydroxyl group can be O-alkylated, O-acylated, or converted to triflates and other leaving groups for further coupling reactions. These attributes make 4-Chloropyridin-3-ol useful in the preparation of pyridine-based pharmaceuticals, agrochemicals, and materials chemistry intermediates.

Always optimize reaction conditions (solvent, base, temperature, and stoichiometry) using small-scale test reactions before scaling up.

Quality Control & Purity Verification

Aladdin Scientific's 4-Chloropyridin-3-ol (SKU: C128912) is characterized prior to dispatch. Recommended in-house purity verification techniques include:

• Thin-Layer Chromatography (TLC): Use silica gel plates with UV visualization (254 nm). A suitable eluent system is ethyl acetate/hexane (1:2 v/v) as a starting point.
• HPLC: Reverse-phase C18 column with UV detection at 254 nm; acetonitrile/water gradient as mobile phase.
• NMR Spectroscopy: ¹H and ¹³C NMR in DMSO-d₆ or CDCl₃ for structural confirmation.
• Melting Point: Determine and compare against literature values as a purity indicator.

If purity does not meet the required specification for a sensitive application, further purification by recrystallization from a suitable solvent (e.g., ethanol/water) or column chromatography may be performed. Contact Aladdin Scientific technical support for the certificate of analysis (CoA).

Frequently asked questions

What solvents are recommended for dissolving 4-Chloropyridin-3-ol?

4-Chloropyridin-3-ol is generally soluble in polar organic solvents such as DMSO, DMF, methanol, and ethanol. For aqueous applications, prepare a concentrated DMSO stock solution and dilute into the aqueous buffer, keeping DMSO below 1% v/v where assay compatibility is required.

How should 4-Chloropyridin-3-ol be stored to maintain stability?

Store the compound in a tightly sealed container at ambient temperature (15–25 °C) in a cool, dry location away from light and moisture. Re-seal under an inert atmosphere such as nitrogen or argon after each use if moisture sensitivity is a concern. Avoid exposure to strong oxidizers or strong bases.

What are the primary synthetic uses of 4-Chloropyridin-3-ol?

The compound is used as a bifunctional building block in medicinal and synthetic chemistry. The C-4 chloro group undergoes nucleophilic aromatic substitution (SNAr) with amines, thiols, and alkoxides, while the 3-hydroxyl group can be O-alkylated, O-acylated, or converted to leaving groups for cross-coupling reactions, enabling access to diverse pyridine-based structures.

How can I verify the purity of 4-Chloropyridin-3-ol upon receipt?

Request the Certificate of Analysis (CoA) from Aladdin Scientific for the specific lot. In-house verification can be performed by TLC (silica gel, UV 254 nm), reverse-phase HPLC with UV detection, ¹H NMR spectroscopic analysis, or melting point determination and comparison with reference values.

Is 4-Chloropyridin-3-ol hazardous, and what PPE is required?

As with most halogenated heterocyclic compounds, 4-Chloropyridin-3-ol should be treated as a potential irritant. Always wear nitrile gloves, a laboratory coat, and safety goggles when handling. Work under a fume hood to avoid dust or vapor inhalation, and consult the product SDS for full hazard information before use.

References

1. Clayden, J.; Greeves, N.; Warren, S. Organic Chemistry, 2nd ed.; Oxford University Press: Oxford, 2012. (General reference for nucleophilic aromatic substitution and heterocyclic chemistry.)
2. Aladdin Scientific. Certificate of Analysis for 4-Chloropyridin-3-ol, SKU C128912. (Consult current CoA for lot-specific purity and characterization data.)

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.