5-Chlorothiophene-2-carboxylic acid
[CAS# 24065-33-6]

Identification

• Classification: Chemical reagent >> Organic reagent >> Aromatic acid
• Name: 5-Chlorothiophene-2-carboxylic acid
• Synonyms: 5-Chloro-2-thiophenecarboxylic acid
• Molecular Formula: C₅H₃ClO₂S
• Molecular Weight: 162.59
• CAS Registry Number: 24065-33-6
• EC Number: 480-060-6
• SMILES: C1=C(SC(=C1)Cl)C(=O)O

Properties

• Melting point: 146-150 °C

Safety Data

• Hazard Symbols: GHS05;GHS07 Danger
• Risk Statements: H302-H315-H317-H318-H319-H335
• Safety Statements: P261-P264-P264+P265-P270-P271-P272-P280-P301+P317-P302+P352-P304+P340-P305+P351+P338-P305+P354+P338-P317-P319-P321-P330-P332+P317-P333+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H302
Skin irritation	Skin Irrit.	2	H315
Serious eye damage	Eye Dam.	1	H318
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin sensitization	Skin Sens.	1	H317
Eye irritation	Eye Irrit.	2A	H319

Discovery and Applications

5-Chlorothiophene-2-carboxylic acid is an important chemical compound within the field of organosulfur chemistry, known for its unique structure and diverse applications. This compound features a thiophene ring substituted with both a chlorine atom and a carboxylic acid group, which imparts significant reactivity and utility.

The discovery of 5-chlorothiophene-2-carboxylic acid originated from efforts to explore new functionalized thiophene derivatives. The synthesis of this compound typically involves chlorination of thiophene-2-carboxylic acid or related precursors. The introduction of the chlorine atom at the 5-position of the thiophene ring results in a compound with enhanced reactivity and functional properties, making it valuable for various chemical applications.

In organic synthesis, 5-chlorothiophene-2-carboxylic acid serves as a crucial building block for the preparation of more complex molecules. Its carboxylic acid group allows for further functionalization and transformation, making it a versatile intermediate in the synthesis of pharmaceuticals, agrochemicals, and advanced materials. For example, the compound can be used in the synthesis of thiophene-based ligands for metal-catalyzed reactions, or as a precursor for the development of bioactive molecules.

The compound is also significant in materials science, where it is employed in the development of organic semiconductors and conducting polymers. The presence of the carboxylic acid group facilitates the formation of strong interactions with other polymer components or substrates, while the chlorine atom can influence the electronic properties of the material. This makes 5-chlorothiophene-2-carboxylic acid useful in the creation of materials with tailored electrical and optical properties for applications in electronic devices and sensors.

In medicinal chemistry, derivatives of 5-chlorothiophene-2-carboxylic acid have been investigated for their potential biological activity. The compound's ability to act as a precursor for various thiophene-based pharmaceuticals has led to its exploration in the development of drugs with antimicrobial, anti-inflammatory, or anticancer properties. The functional groups present in the compound contribute to its interaction with biological targets, making it a valuable component in drug discovery.

Overall, 5-chlorothiophene-2-carboxylic acid is a versatile and valuable compound with applications spanning organic synthesis, materials science, and medicinal chemistry. Its unique structure and functional groups enhance its utility in various chemical processes and the development of advanced materials and pharmaceuticals.

References

2024. L-Phenylalanine-tethered Peptide Hydrazones of Chloro-based Thiophene-2-carboxamides: Design, Synthesis, and Anti-Microbial Studies. *Russian Journal of Organic Chemistry*, 60(7).
DOI: 10.1134/s1070428024070248

2016. Comparison of the Hydrolysis and Esterification Methods for the Determination of Genotoxic 5-Chlorothiophene-2-Carbonyl Chloride in Rivaroxaban Using HPLC. *Chromatographia*, 79(3-4).
DOI: 10.1007/s10337-016-3038-8

2013. Supramolecular architectures and structural diversity in a series of lead (II) Chelates involving 5-Chloro/Bromo thiophene-2-carboxylate and N,N’-donor ligands. *Chemistry Central Journal*, 7(139).
DOI: 10.1186/1752-153x-7-139