(S)-2-(4-(Piperidin-3-yl)phenyl)-2H-indazole-7-carboxamide Hydrochloride

This compound is typically isolated as an off-white to pale beige crystalline powder. Its molecular formula is C19H21ClN4O, corresponding to a molecular weight of 356.85. The melting point is not sharply defined and generally exceeds 200 °C, with decomposition occurring upon heating. The calculated density is approximately 1.3 g/cm³ under ambient conditions. It exhibits good solubility in water and polar organic solvents such as methanol, ethanol, and dimethyl sulfoxide due to the hydrochloride salt form, while showing limited solubility in aprotic solvents like acetonitrile and negligible solubility in non-polar hydrocarbons. The molecule contains both hydrogen bond donors and acceptors from the carboxamide and indazole moieties. The hydrochloride salt enhances aqueous solubility and stability. Storage in a tightly sealed container under inert atmosphere at reduced temperature (2–8 °C) is recommended to prevent hygroscopic absorption and degradation. Contact with strong oxidizing agents and strong bases should be avoided.

(S)-2-(4-(Piperidin-3-yl)phenyl)-2H-indazole-7-carboxamide hydrochloride features a chiral piperidine ring connected through a para-substituted phenyl linker to the 2-position of an indazole core, which carries a carboxamide group at the 7-position. The (S)-configuration at the piperidine 3-position imparts defined three-dimensionality, crucial for enantioselective recognition by biological targets. The indazole ring system combines a pyrazole fused to a benzene, offering both hydrogen-bonding capacity through the pyrazole-type nitrogen and π-stacking interactions via the aromatic surface. The carboxamide provides additional hydrogen-bonding sites. The hydrochloride salt form facilitates formulation and improves pharmacokinetic handling. This architectural blend of a basic chiral amine, a rigid heteroaromatic core, and a polar amide makes the compound a versatile intermediate in the synthesis of complex pharmacologically active molecules.

Kinase Inhibitor Synthesis
The indazole scaffold is a well-recognized motif in the design of ATP-competitive kinase inhibitors. This compound serves as a key building block for introducing the chiral piperidinylphenyl group into drug candidates targeting kinases involved in oncology and inflammatory disorders. The carboxamide can engage in critical hydrogen bonds with hinge region residues, while the piperidine nitrogen offers a handle for further functionalization to modulate selectivity and potency.

Central Nervous System Agent Development
The chiral piperidine fragment is structurally related to pharmacophores found in numerous CNS-active compounds. Derivatives of this scaffold are investigated for their affinity to G-protein coupled receptors and ion channels, including serotonin and dopamine receptors. The spatial arrangement of the basic amine and aromatic rings mimics the topology of endogenous neurotransmitters, enabling the design of novel antipsychotics and antidepressants.

Asymmetric Synthesis Chiron
The well-defined (S)-stereocenter makes this compound a valuable starting material for preparing enantiomerically pure ligands and organocatalysts. After deprotection or further functionalization, it can be incorporated into chiral auxiliaries used in asymmetric hydrogenation, allylic alkylation, and other stereoselective transformations.

Chemical Biology Probe
The combination of a fluorescent indazole core and a basic piperidine allows this molecule to serve as a template for developing molecular probes. By attaching reporter groups or affinity tags via the carboxamide or piperidine nitrogen, researchers can create tools to study protein-ligand interactions, receptor localization, and signal transduction pathways involving purinergic or kinase targets.