Description

4-Isoxazolecarbonyl Chloride, 3-Ethyl- (9Ci) is a versatile and highly reactive organic acid chloride derivative of an isoxazole ring system. This compound serves as a critical building block in advanced organic synthesis, enabling the efficient introduction of the 3-ethylisoxazole-4-carbonyl moiety into target molecules. It is primarily sought after by research chemists and process development scientists in the pharmaceutical and agrochemical industries for the synthesis of novel active ingredients, heterocyclic libraries, and complex intermediates. The CAS number for this compound is 99803-70-0.

Application

• Pharmaceutical Intermediate: Key building block for the synthesis of novel drug candidates, particularly in medicinal chemistry programs targeting enzyme inhibitors and receptor modulators.
• Agrochemical Synthesis: Used in the research and development of new herbicides, fungicides, and insecticides that incorporate the isoxazole heterocycle for enhanced bioactivity.
• Chemical Research & Development: A valuable reagent for constructing complex heterocyclic scaffolds and for use in amide coupling reactions to create diverse compound libraries.
• Material Science Precursor: Potential intermediate in the synthesis of specialized polymers or ligands with unique electronic or coordination properties.

Basic Information

Product Name	4-Isoxazolecarbonyl Chloride, 3-Ethyl- (9Ci)
CAS No.	99803-70-0
Molecular Formula	C6H6ClNO2
Molecular Weight	159.57 g/mol
Synonyms	3-Ethyl-4-isoxazolecarbonyl chloride; 3-Ethylisoxazole-4-carbonyl chloride; 3-Ethyl-1,2-oxazole-4-carbonyl chloride; 4-Carboxy-3-ethylisoxazole chloride; 99803-70-0; 3-Ethyl-4-isoxazole carboxylic acid chloride
EINECS	Contact for details

Quality Control

Our 4-Isoxazolecarbonyl Chloride, 3-Ethyl- (9Ci) is produced under strict quality management protocols. Each batch undergoes comprehensive analytical testing, including chromatographic purity analysis and identity confirmation, to ensure it meets the high standards required for research and development applications. A Certificate of Analysis (COA) detailing specific results for purity, assay, and impurity profiles is provided with every shipment to guarantee traceability and consistency.

Storage

Preserve in a tightly closed container, protected from light. Due to its hygroscopic (moisture-sensitive) nature and reactivity as an acid chloride, the material must be stored under an inert atmosphere (e.g., nitrogen or argon) in a cool, dry, and well-ventilated place. Recommended storage temperature is 2-8°C for long-term stability. Keep away from strong bases, alcohols, and moisture.

Specification

Item	Specification
Appearance	Colorless to pale yellow liquid or solid
Identification (IR)	Conforms to structure
Purity (HPLC)	≥ 95.0%
Water Content (KF)	≤ 0.5%

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