3-Amino-2,5-dichloropyridine (CAS 72287-26-4): Synthesis Routes and Applications of a Key Chloropyridine Building Block
Dichloroaminopyridines are among the most versatile small heterocycles in discovery chemistry: the amino group offers a handle for amide, sulfonamide, and urea formation, while each C–Cl bond is a latent cross-coupling site. 3-Amino-2,5-dichloropyridine combines these features in one compact scaffold, which is why it appears repeatedly in medicinal chemistry programs as a divergent intermediate.
For procurement teams, the compound sits in a practical middle zone: it is commercially available from multiple suppliers, yet consistent regioisomer purity — the difference between useful material and a purification problem — varies significantly between sources.
Chemical Identity and Key Properties
| Property | Value |
|---|---|
| CAS Number | 72287-26-4 |
| Molecular Formula | C5H4Cl2N2 |
| Molecular Weight | 161.98 g/mol |
Regioselective Functionalization Patterns
The two chlorines at the 2- and 5-positions differ in reactivity. Under palladium-catalyzed conditions (Suzuki, Buchwald–Hartwig, Negishi), oxidative addition typically proceeds faster at the more activated position adjacent to the ring nitrogen, allowing sequential, selective functionalization. The amino group can be temporarily protected (Boc or acyl) when harsher conditions are required, then deprotected under standard acid or base conditions.
This substitution pattern makes the molecule a standard starting point for tricyclic cores: condensation of the amino group with carboxylic acid derivatives or ortho-functionalized electrophiles delivers fused imidazo-, pyrido-, and quinazoline-type scaffolds frequently seen in kinase inhibitor and CNS programs.
Application Areas
Pharmaceutical Intermediates
Aminopyridine derivatives are prevalent in APIs targeting kinases, ion channels, and CNS receptors. The 2,5-dichloro pattern allows late-stage diversification during SAR exploration.
Agrochemical Discovery
Chloropyridine motifs are present in multiple commercial insecticides and fungicides; the scaffold supports systematic analog libraries for crop-protection screening.
Ligand and Material Chemistry
Aminopyridines serve as precursors to N-heterocyclic carbenes, chelating ligands, and pyridine-functionalized materials.
Manufacturing Considerations
Industrial routes generally start from commodity pyridines and proceed through controlled chlorination or amination chemistry; the key cost drivers are regioisomer control and purification (crystallization or distillation). Impurity profiles worth monitoring include the isomeric dichloroaminopyridines and residual chlorinated by-products from the final step.
Frequently Asked Questions
What impurities matter most in 3-amino-2,5-dichloropyridine?
Regioisomeric aminopyridines are the primary concern because they co-elude in crude HPLC methods. Suppliers should provide an isomer-specific assay and a full impurity listing on the COA.
What purity is typically available?
Standard catalog material is ≥98% by HPLC with GC or qNMR cross-check; higher grades for GMP programs are available on request.
Can this compound be custom synthesized at scale?
Yes. CoreyChem manufactures 3-amino-2,5-dichloropyridine and related chloropyridines from gram to multi-kilogram quantities with full documentation (COA, MSDS, HPLC/NMR).
Source from CoreyChem
CoreyChem supplies 3-Amino-2,5-dichloropyridine (CAS 72287-26-4) with lot-specific COA and MSDS documentation. Custom synthesis, higher purity grades, and bulk packaging are available on request — contact our technical team with your target specification and quantity for current lead time and pricing.