6-Chloropyridazin-3-amine
[CAS# 5469-69-2]

Identification

• Classification: Pharmaceutical intermediate >> Heterocyclic compound intermediate >> Pyridazine
• Name: 6-Chloropyridazin-3-amine
• Synonyms: 3-Amino-6-chloropyridazine
• Molecular Formula: C₄H₄ClN₃
• Molecular Weight: 129.55
• CAS Registry Number: 5469-69-2
• EC Number: 226-796-1
• SMILES: C1=CC(=NN=C1N)Cl

Properties

• Density: 1.4±0.1 g/cm³ Calc.^*
• Melting point: 215 - 220 °C (Expl.)
• Boiling point: 363.2±22.0 °C 760 mmHg (Calc.)^*
• Flash point: 173.4±22.3 °C (Calc.)^*
• Index of refraction: 1.618 (Calc.)^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

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

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2	H319
Acute toxicity	Acute Tox.	4	H302
Eye irritation	Eye Irrit.	2A	H319
Acute toxicity	Acute Tox.	4	H332
Acute toxicity	Acute Tox.	4	H312

Discovery and Applications

6-Chloropyridazin-3-amine is a chemical compound belonging to the class of pyridazine derivatives. It consists of a pyridazine ring, which is a six-membered heterocyclic structure containing two nitrogen atoms, with a chlorine atom attached to the 6-position and an amine group (-NH2) at the 3-position. This structural arrangement makes it a functionalized pyridazine derivative with potential applications in various fields, including organic synthesis, pharmaceuticals, and materials science.

The synthesis of 6-chloropyridazin-3-amine typically involves halogenation of pyridazine, followed by selective introduction of the amine group. The chlorination step is often carried out using reagents such as chlorine gas or a chlorinating agent, which introduce the chlorine atom at the desired position. The amine group can be introduced through standard amination techniques, utilizing either a direct reaction with an appropriate amine or through the use of reagents that facilitate nucleophilic substitution at the 3-position of the pyridazine ring.

This compound is of particular interest in medicinal chemistry due to the presence of both a halogen (chlorine) and an amine group. The combination of these functional groups can impart unique reactivity and biological activity to the molecule. The amine group, being a nucleophilic site, can participate in a variety of chemical reactions, including the formation of salts, coordination complexes, or other derivatives. Meanwhile, the chlorine atom can influence the compound's lipophilicity, reactivity, and interaction with biological targets.

6-Chloropyridazin-3-amine has been studied in the context of drug discovery, particularly for its potential as a building block in the synthesis of biologically active compounds. Pyridazine derivatives are known to exhibit a range of pharmacological properties, including antimicrobial, anti-inflammatory, and anticancer activities. The presence of the amine group enhances the compound's ability to engage in interactions with various biological molecules, such as enzymes or receptors, which may explain its potential therapeutic applications.

Moreover, this compound could be a useful intermediate in the synthesis of more complex pyridazine-based pharmaceuticals or agrochemicals. By modifying the functional groups on the pyridazine ring, it is possible to tailor the compound's properties for specific applications. The ability to easily functionalize the amine and halogen groups provides synthetic flexibility, which is beneficial in designing compounds with improved potency, selectivity, and pharmacokinetic properties.

Additionally, 6-chloropyridazin-3-amine may find applications in materials science. Pyridazine derivatives are sometimes used in the development of new materials with specific electronic, optical, or conductive properties. By incorporating functional groups such as amines and halogens, the chemical properties of these materials can be tuned to suit specific industrial needs, such as in the creation of polymers, coatings, or sensors.

In summary, 6-chloropyridazin-3-amine is a versatile and potentially valuable compound in both synthetic and pharmaceutical chemistry. Its ability to undergo various chemical transformations, along with its presence in biologically active molecules, makes it a promising candidate for further study in drug development and materials science.

References

2006. Palladium-Catalysed Cross-Coupling Reactions on Pyridazine Moieties. Synlett, 2006(17).
DOI: 10.1055/s-2006-951528

2011. First Synthesis of 3-Amino-2-arylimidazo[1,2-b]pyridazines by Groebke-Blackburn Reaction. Synlett, 2011(10).
DOI: 10.1055/s-0030-1260940

2023. Synthesis, Crystal Structure, and DFT Study of Ethyl 6-Chloro-3-fluoroimidazo[1,2-b]pyridazine-2-carboxylate. Russian Journal of General Chemistry, 93(5).
DOI: 10.1134/s1070363223050201