New C‐3 Substituted 1H‐ and 2H‐Indazolephosphonic Acid Regioisomers: Synthesis, Spectroscopic Characterization and X‐Ray Diffraction Studies. Issue 36 (26th September 2021)

• Record Type: Journal Article
• Authors: Teixeira, Fátima C.; Antunes, Inês F.; Curto, M. João M.; Duarte, M. Teresa; André, Vânia; Teixeira, António P. S.
• Is Part Of: ChemistrySelect. Volume 6:Issue 36(2021)
• Page Start: 9599
• Page End: 9607
• Publication Date: 2021-09-26
• Subjects: Indazole -- Phosphorus heterocycles -- Regioselectivity -- Structure elucidation -- X-ray diffraction; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.202102538
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: Indazole is known as an important structural motif in medicinal chemistry and, recently, has also gained attention in other areas, such as materials chemistry, with many studies showing different potential applications for their regioisomers. Phosphonates are also a class of compounds with diverse applications, ranging from medicinal to material applications. Here we present the synthesis of 1 H ‐ and 2 H ‐indazolephosphonic acid derivatives substituted at C‐3, involving mono‐ or bisphosphonic acids, from their corresponding carboxylic acid and esters. These compounds were fully characterized, and their spectroscopic data were evaluated to identify and distinguish the structural scaffold of each phosphonic acid. Crystallization of [hydroxy(1‐methyl‐1 H ‐indazol‐3‐yl)methanediyl]bis(phosphonic acid) 7 afforded crystals suitable for single crystal X‐ray diffraction studies and its crystal structure details are also discussed. Abstract : 1 H ‐ and 2 H ‐indazolephosphonic acid derivatives substituted at C‐3, involving mono‐ or bisphosphonic acids were prepared and characterized. Spectroscopic data were evaluated to identify and distinguish the structural scaffold of phosphonic acid regioisomers. The structure of [hydroxy(1‐methyl‐1 H ‐indazol‐3‐yl)methanediyl]bis(phosphonic acid) was confirmed by X‐ray diffraction studies.