1H-Pyrazole-4-sulfonyl chloride
1H-Pyrazole-4-sulfonyl chloride (CAS: 288148-34-5; Formula: C3H3ClN2O2S) is a heterocyclic organic compound with a molecular weight of 166.59 g/mol. It serves as a valuable building block in organic synthesis, particularly for the construction of more complex molecules containing the pyrazole moiety. Its sulfonyl chloride functional group makes it reactive towards nucleophiles, enabling its incorporation into various chemical structures.

Chemical Synthesis Intermediate
This compound is primarily used as an intermediate in the synthesis of diverse organic molecules. The reactive sulfonyl chloride group facilitates its participation in various coupling and functionalisation reactions.
Heterocyclic Chemistry
As a pyrazole derivative, it is employed in the development of novel heterocyclic compounds. These structures are often explored for their potential applications in medicinal chemistry and materials science.
Building Block for Pharmaceuticals
The pyrazole scaffold is present in numerous pharmaceutically active compounds. 1H-Pyrazole-4-sulfonyl chloride can be a key starting material or intermediate for synthesising potential drug candidates.
| Molecular weight | 166.59 |
|---|---|
| Empirical formula | C3H3ClN2O2S |

Hazard statements
- H317May cause an allergic skin reaction
Precautionary statements
- P280Wear protective gloves, clothing and eye/face protection
| Water hazard class (WGK, DE) | 3 |
|---|---|
| Hazard codes (EU) | Xi |
| Risk statements (R) | 43 |
| Safety statements (S) | 36/37 |
Hazard information is provided for guidance. Always consult the product Safety Data Sheet (SDS), available on request, before handling.
Documentation
Every batch ships with a Certificate of Analysis covering assay, identity and purity; the grade is confirmed against your enquiry. Safety Data Sheets and technical data sheets are available on request.
Supply & logistics
Samples for technical evaluation; bulk MOQ by grade and packaging. In-stock material ships in 7–10 working days, worldwide, with full export documentation.
What is 1H-Pyrazole-4-sulfonyl chloride used for?
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1H-Pyrazole-4-sulfonyl chloride is used as a versatile building block in organic synthesis, particularly for creating complex molecules containing the pyrazole ring system. It is also applied in heterocyclic chemistry and as an intermediate for potential pharmaceutical compounds.
What is the CAS number and chemical formula for 1H-Pyrazole-4-sulfonyl chloride?
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The CAS number for 1H-Pyrazole-4-sulfonyl chloride is 288148-34-5, and its chemical formula is C3H3ClN2O2S.
What grade and purity does Tech Serve Solutions supply?
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Tech Serve Solutions supplies this chemical for research and development purposes. Specific assay and purity information are available on the product's Certificate of Analysis. It is not supplied as USP, BP, EP, or any other pharmacopoeia grade.
How should 1H-Pyrazole-4-sulfonyl chloride be handled?
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1H-Pyrazole-4-sulfonyl chloride is classified as a Warning (GHS07). It may cause an allergic skin reaction (H317). Handle with appropriate personal protective equipment, including gloves and eye protection, in a well-ventilated area to avoid skin contact and inhalation. Refer to the Safety Data Sheet for detailed handling instructions.
Is 1H-Pyrazole-4-sulfonyl chloride a controlled substance?
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The provided data does not indicate that 1H-Pyrazole-4-sulfonyl chloride is a controlled substance.
How is 1H-Pyrazole-4-sulfonyl chloride packed and shipped?
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Products are carefully packed according to international shipping regulations for chemicals. Tech Serve Solutions exports globally, ensuring compliance with all relevant transport and customs requirements.
How can I request a sample or quote for 1H-Pyrazole-4-sulfonyl chloride?
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To request a sample or a quote, please contact our sales team through the website or by phone. Please include the product name and CAS number in your request.
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