Overview and Chemical Properties

Methyl 1H-pyrazole-4-carboxylate hydrochloride (SKU: M734566) is a heterocyclic compound featuring a five-membered pyrazole ring bearing a methyl ester substituent at the 4-position, presented as its hydrochloride salt. The hydrochloride salt form generally improves stability and ease of handling compared to the free base. This compound serves as a key intermediate and building block in the synthesis of pharmaceutically relevant molecules, agrochemicals, and functional materials. Researchers should consult the product-specific Safety Data Sheet (SDS) and Certificate of Analysis (CoA) for confirmed physicochemical data including molecular weight, melting point, and purity.

Safety and Handling Precautions

Before working with Methyl 1H-pyrazole-4-carboxylate hydrochloride, always review the current SDS provided by Aladdin Scientific. Standard laboratory personal protective equipment (PPE) should be worn at all times, including chemical-resistant gloves, a laboratory coat, and safety goggles. Work should be conducted in a well-ventilated area or a fume hood, particularly when weighing powdered material to minimize inhalation exposure. Avoid contact with skin, eyes, and mucous membranes. In the event of skin or eye contact, flush immediately with copious amounts of water and seek medical attention as appropriate. Dispose of waste in accordance with local regulations governing heterocyclic organic compounds and hydrochloride salts.

Storage Conditions

Store Methyl 1H-pyrazole-4-carboxylate hydrochloride in a tightly sealed container in a cool, dry location away from direct light, heat sources, and moisture. Hydrochloride salts of heterocyclic esters may be susceptible to hydrolysis under humid conditions; therefore, desiccants such as silica gel or molecular sieves are recommended within the storage environment. Always confirm specific storage temperature requirements (e.g., room temperature, 2–8 °C, or −20 °C) on the product label and CoA. After each use, reseal the container promptly and return it to recommended storage conditions to maintain compound integrity and purity.

Dissolution and Solution Preparation Protocol

The following general protocol is recommended for preparing stock solutions of Methyl 1H-pyrazole-4-carboxylate hydrochloride:

1. Equilibrate to room temperature: Allow the sealed vial to equilibrate to room temperature before opening to prevent moisture condensation on the compound.
2. Weigh accurately: Using a calibrated analytical balance, weigh the required amount of compound in a suitable tared vessel inside a fume hood.
3. Solvent selection: As a hydrochloride salt, this compound is expected to exhibit good solubility in water and polar protic solvents such as methanol and ethanol. For applications requiring anhydrous conditions, dimethyl sulfoxide (DMSO) may be considered. Verify solubility experimentally for each solvent system.
4. Dissolution: Add the chosen solvent gradually to the weighed compound with gentle swirling or vortexing. If complete dissolution is not achieved, brief sonication in a water bath may be employed.
5. Filtration (if required): Filter the solution through a 0.22 µm syringe filter if particulates are observed.
6. Concentration verification: Confirm the final concentration using UV-Vis spectrophotometry or another appropriate analytical technique.
7. Aliquot and store: Prepare single-use aliquots to avoid repeated freeze-thaw cycles that could degrade compound integrity.

Note: All solubility values should be verified experimentally. Consult the CoA for purity information before calculating molar concentrations.

Typical Applications in Synthesis

Methyl 1H-pyrazole-4-carboxylate hydrochloride is valued in synthetic chemistry primarily for the following applications:

• Pharmaceutical intermediate synthesis: The pyrazole scaffold is a privileged heterocyclic framework present in numerous bioactive molecules and FDA-approved drugs. This compound provides a functionalized entry point for elaboration into more complex structures via N-alkylation, ester hydrolysis, amide coupling, or cycloaddition chemistry.
• Agrochemical research: Pyrazole-based compounds are important in the development of herbicides, fungicides, and insecticides.
• Materials science: Pyrazole-4-carboxylate motifs have been explored as ligands in coordination chemistry and metal-organic framework (MOF) construction.
• Medicinal chemistry SAR studies: The compound enables structure-activity relationship (SAR) explorations through functional group transformations at the ester and ring nitrogen positions.

Researchers are encouraged to consult primary literature for specific reaction conditions and yields relevant to their target transformations.