Description

1H-Pyrazole-5-Carbonyl Chloride, 4-Chloro-1-Methyl- (9Ci) is a versatile and highly reactive chemical building block, specifically an acyl chloride derivative of a substituted pyrazole. Its core value proposition lies in its ability to efficiently introduce the 4-chloro-1-methylpyrazole-5-carbonyl moiety into target molecules, enabling the synthesis of complex heterocyclic compounds. This intermediate is critically needed by research chemists and process development scientists in the pharmaceutical and agrochemical industries for constructing novel active ingredients and fine chemicals. Its precise structure offers a strategic handle for further functionalization in advanced synthetic routes.

Application

• Pharmaceutical Intermediate: Key building block for the synthesis of novel drug candidates, particularly in medicinal chemistry programs targeting enzyme inhibition.
• Agrochemical Synthesis: Used in the research and development of next-generation herbicides, fungicides, and insecticides that require specific heterocyclic scaffolds.
• Organic Synthesis Reagent: Serves as a versatile acylating agent in academic and industrial laboratories for creating amides, esters, and other carbonyl-containing derivatives.
• Material Science Research: Potential precursor for the development of specialized polymers, ligands for catalysis, or organic electronic materials with tailored properties.
• Chemical Biology Probes: Useful for labeling or modifying biomolecules to study biological pathways and protein function.

Basic Information

Product Name	1H-Pyrazole-5-Carbonyl Chloride, 4-Chloro-1-Methyl- (9Ci)
CAS No.	157142-50-2
Molecular Formula	C5H4Cl2N2O
Molecular Weight	178.99 g/mol
Synonyms	4-Chloro-1-methyl-1H-pyrazole-5-carbonyl chloride; 4-Chloro-1-methylpyrazole-5-carbonyl chloride; 1-Methyl-4-chloro-1H-pyrazole-5-carbonyl chloride; 4-Chloro-1-methyl-1H-pyrazole-5-carboxylic acid chloride; 1-Methyl-4-chloropyrazole-5-carbonyl chloride; 5-(Chlorocarbonyl)-4-chloro-1-methylpyrazole; 4-Chloro-1-methylpyrazole-5-carboxylic acid chloride
EINECS	Contact for details

Quality Control

Our production of 1H-Pyrazole-5-Carbonyl Chloride, 4-Chloro-1-Methyl- (9Ci) adheres to stringent quality control protocols to ensure batch-to-batch consistency and high purity, which is critical for sensitive synthetic applications. Each lot is analyzed using advanced chromatographic and spectroscopic techniques. Certificates of Analysis (COA) detailing purity, identity, and impurity profiles are provided with every shipment to support your quality assurance and regulatory documentation needs.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated place. Due to its hygroscopic (moisture-sensitive) nature and reactivity as a strong acid/organic solvent derivative, the container must be kept tightly sealed under an inert atmosphere (e.g., nitrogen or argon) after opening to prevent decomposition. Recommended storage temperature is 2-8°C for long-term stability.

Specification

Item	Specification
Appearance	White to off-white crystalline solid or powder
Identification (IR)	Conforms to structure
Purity (HPLC)	≥ 97.0%
Water Content (KF)	≤ 0.5%
Related Substances (HPLC)	Individual impurity ≤ 1.0%; Total impurities ≤ 3.0%

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.