5-Chloropyrazine-2-carboxylic acid
[CAS# 36070-80-1]

Identification

• Classification: Pharmaceutical intermediate >> Heterocyclic compound intermediate >> Pyrazines
• Name: 5-Chloropyrazine-2-carboxylic acid
• Synonyms: 5-Chloro-2-pyrazinecarboxylic acid
• Molecular Formula: C₅H₃ClN₂O₂
• Molecular Weight: 158.54
• CAS Registry Number: 36070-80-1
• EC Number: 636-844-7
• SMILES: C1=C(N=CC(=N1)Cl)C(=O)O

Properties

• Melting point: 150-160 °C (decomp.)
• Boiling point: 330.9 °C (760 mmHg)

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H319-H335
• Safety Statements: P261-P264-P264+P265-P271-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Eye irritation	Eye Irrit.	2A	H319

Discovery and Applications

5-Chloropyrazine-2-carboxylic acid is an important compound in the field of heterocyclic chemistry. The compound features a chlorine atom at the 5-position and a carboxylic acid group at the 2-position of the pyrazine ring and was first synthesized during a study investigating the properties and potential applications of chlorinated pyrazine derivatives. The combination of the chlorine atom and the carboxylic acid group on the pyrazine ring gives the molecule a unique chemical reactivity and versatility, making it a valuable building block in a variety of chemical applications.

The synthesis of 5-chloropyrazine-2-carboxylic acid involves the chlorination of pyrazine-2-carboxylic acid. A common synthetic route is to introduce a chlorine atom at the 5-position of the pyrazine ring using a chlorinating agent such as phosphorus pentachloride (PCl5) or thionyl chloride (SOCl2). The starting material, pyrazine-2-carboxylic acid, is readily available and can be chlorinated to efficiently generate 5-chloropyrazine-2-carboxylic acid.

5-Chloropyrazine-2-carboxylic acid has a wide range of applications, especially in the pharmaceutical and agrochemical industries, due to its unique chemical structure and reactivity.

In medicinal chemistry, 5-chloropyrazine-2-carboxylic acid is an important intermediate in the synthesis of various bioactive molecules. The pyrazine core structure is essential for the development of drugs with antimicrobial, anticancer, and anti-inflammatory properties. The chlorine and carboxylic acid functional groups enhance its reactivity, allowing for further modifications to optimize pharmacological properties and improve drug efficacy.

This compound is also of great importance in the production of agrochemicals, including herbicides, insecticides, and fungicides. Its ability to interfere with the biological processes of pests and pathogens makes it an active ingredient in formulations to protect crops and increase agricultural productivity. The chlorinated pyrazine structure is particularly useful for the development of compounds with enhanced potency and environmental stability.

In addition to its direct applications, 5-chloropyrazine-2-carboxylic acid is frequently used in chemical research as a building block for the synthesis of more complex molecules. It is used to study reaction mechanisms and develop new synthetic methods. Its reactivity and versatility make it a valuable compound for exploring new chemical reactions and creating innovative compounds.

Ongoing research on 5-chloropyrazine-2-carboxylic acid is expected to further expand its range of applications. Future research focuses on optimizing its synthesis, exploring new derivatives, and improving its efficacy in various applications. The development of novel compounds based on this structure will lead to breakthroughs in drug discovery, agrochemical development, and materials science.

References

2021. Functionalization of Pyrazines. Synthesis, 53(14).
DOI: 10.1055/s-0040-1706545