NINGBO INNO PHARMCHEM CO.,LTD. offers a detailed exploration of the chemical reactivity and advanced spectroscopic analysis of 6-Nitroindazole (CAS 7597-18-4). Understanding these aspects is crucial for its effective utilization in synthesis and research.

The chemical reactivity of 6-Nitroindazole is largely dictated by the presence of the nitro group at the 6-position. This electron-withdrawing group significantly influences the electron distribution within the indazole ring system. It activates the ring towards nucleophilic aromatic substitution (SNAr) reactions, particularly at the adjacent 5 and 7 positions. This makes 6-Nitroindazole a valuable substrate for introducing various nucleophilic substituents. The nitro group itself can undergo selective reduction to an amino group, a fundamental transformation that allows for further chemical modifications and the synthesis of diverse derivatives.

Mechanistically, the reduction of the nitro group can be achieved through various methods, including catalytic hydrogenation (e.g., using Pd/C) or chemical reduction with agents like iron or tin. The compound also participates in addition reactions, notably with formaldehyde, forming (1H-indazol-1-yl)methanol derivatives, which provides insight into the reactivity of the indazole N-H moiety.

Advanced spectroscopic techniques are indispensable for the structural elucidation and characterization of 6-Nitroindazole and its derivatives. Nuclear Magnetic Resonance (NMR) spectroscopy, including ¹H NMR and ¹³C NMR, provides detailed information about the molecular structure. The chemical shifts and coupling patterns of protons and carbons are influenced by the electron-withdrawing nitro group, aiding in the confirmation of substitution patterns and connectivity. 2D-NMR techniques like COSY, HSQC, and HMBC are employed to resolve complex spectra and differentiate between isomers.

Infrared (IR) spectroscopy is used to identify characteristic functional groups, with the nitro group typically showing strong absorption bands. Mass Spectrometry (MS) confirms the molecular weight and provides fragmentation data, further supporting structural assignments. X-ray crystallography offers definitive solid-state structural information, detailing bond lengths, angles, and intermolecular interactions. Computational methods like Density Functional Theory (DFT) are also extensively used to predict electronic distribution, reactivity, and thermodynamic stability, complementing experimental findings. Electron Spin Resonance (ESR) spectroscopy and Cyclic Voltammetry (CV) are employed to study the electrochemical behavior and reduction mechanisms of the nitro group, providing insights into its redox properties and potential biological activity.