Chemical Identity and Structural Features

6-Chloro-1H-indol-4-amine (CAS registry number should be verified; see review flags) belongs to the indole family of bicyclic heterocycles, comprising a benzene ring fused to a pyrrole ring. The compound carries two key substituents: a primary amine (–NH₂) at the 4-position and a chlorine atom at the 6-position of the indole scaffold.

The presence of the electron-donating amine group and the electron-withdrawing chloro group on the same aromatic system creates a push–pull electronic environment that influences both the reactivity and the spectroscopic properties of the molecule. The free NH of the indole nitrogen (position 1) provides an additional handle for N-functionalization reactions under appropriate conditions.

Molecular formula: C₈H₇ClN₂; molecular weight: 166.61 g/mol. The compound is expected to exhibit moderate polarity due to the amine functionality, influencing its solubility profile across common laboratory solvents.

Solubility, Storage and Handling Guidelines

Solubility: 6-Chloro-1H-indol-4-amine is expected to be soluble in polar aprotic solvents such as dimethyl sulfoxide (DMSO) and N,N-dimethylformamide (DMF), as well as in lower alcohols such as methanol and ethanol. Solubility in aqueous systems is expected to be limited at neutral pH but may improve under acidic conditions due to protonation of the amine group. Exact solubility values should be experimentally determined for critical applications.

Storage: Store the compound in a tightly sealed container under cool (2–8 °C recommended), dry, and light-protected conditions. Once a container is opened, storage under an inert atmosphere (nitrogen or argon) is advisable to prevent oxidation of the amine functionality and moisture uptake.

Handling precautions: As with all aromatic amine compounds, appropriate personal protective equipment (PPE) including nitrile gloves, safety goggles, and a laboratory coat should be worn. Operations generating dust or aerosols should be performed in a fume hood. Consult the Safety Data Sheet (SDS) for C193389 for full hazard information before use.

Research and Synthetic Applications

6-Chloro-1H-indol-4-amine is primarily valuable as a bifunctional building block in synthetic and medicinal chemistry programs. The two reactive handles—the aryl chloride and the primary amine—allow independent or orthogonal functionalization:

• Cross-coupling reactions: The aryl C–Cl bond can participate in palladium-catalyzed cross-coupling reactions (e.g., Suzuki–Miyaura, Buchwald–Hartwig amination), enabling introduction of aryl, heteroaryl, or amino groups at the 6-position.
• Acylation and sulfonylation: The primary amine at the 4-position can be selectively acylated or sulfonylated to produce amide or sulfonamide derivatives, common motifs in drug discovery.
• N-Alkylation and reductive amination: The amine group provides entry points to secondary and tertiary amine libraries relevant to pharmacological screening.
• Indole N-functionalization: The indole NH can be protected or functionalized to modulate electronic and physical properties.

The indole scaffold itself is a privileged structure in medicinal chemistry, appearing in numerous bioactive natural products and approved pharmaceuticals. Halogenated indole amines are frequently used as precursors in the synthesis of kinase inhibitors, receptor modulators, and other therapeutic agents. Specific biological activities of 6-Chloro-1H-indol-4-amine itself require experimental validation.

Quality, Purity and Analytical Considerations

For research applications, the purity of 6-Chloro-1H-indol-4-amine is a critical parameter. Researchers should confirm purity by at least one analytical technique prior to use in sensitive assays. Recommended analytical methods include:

• HPLC (High-Performance Liquid Chromatography): Reversed-phase HPLC with UV detection is the standard method for assessing chemical purity. A purity of ≥95% is generally acceptable for synthetic applications; ≥98% may be required for biological testing.
• NMR Spectroscopy: ¹H and ¹³C NMR spectra confirm structural identity and detect common impurities or solvent residues.
• Mass Spectrometry: ESI-MS or APCI-MS confirms molecular weight and detects halogen isotope patterns characteristic of mono-chlorinated compounds (M and M+2 peaks in approximately 3:1 ratio).
• Melting Point: A sharp melting point consistent with the literature value (to be verified; see review flags) is indicative of high purity.

Aladdin Scientific provides Certificate of Analysis (CoA) data for each lot of C193389. Researchers are encouraged to request CoA documentation at the time of ordering to verify that the supplied material meets the specifications required for their application.