Indazole

Indazole, also called isoindazole, is a heterocyclic aromatic organic compound. This bicyclic compound consists of the fusion of benzene and pyrazole.

Indazole
Skeletal formula with numbering convention
Ball-and-stick model
Space-filling model
Names
Preferred IUPAC name
1H-Indazole[1]
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard100.005.436 Edit this at Wikidata
UNII
  • InChI=1S/C7H6N2/c1-2-4-7-6(3-1)5-8-9-7/h1-5H,(H,8,9) checkY
    Key: BAXOFTOLAUCFNW-UHFFFAOYSA-N checkY
  • InChI=1/C7H6N2/c1-2-4-7-6(3-1)5-8-9-7/h1-5H,(H,8,9)
    Key: BAXOFTOLAUCFNW-UHFFFAOYAQ
  • c2ccc1[nH]ncc1c2
Properties
C7H6N2
Molar mass118.14 g/mol
Melting point147 to 149 °C (297 to 300 °F; 420 to 422 K)
Boiling point270 °C (518 °F; 543 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Indazole is an amphoteric molecule which can be protonated to an indazolium cation or deprotonated to an indazolate anion. The corresponding pKa values are 1.04 for the equilibrium between indazolium cation and indazole and 13.86 for the equilibrium between indazole and indazolate anion.[2]

Indazole derivatives display a broad variety of biological activities.

Indazoles are rare in nature. The alkaloids nigellicine, nigeglanine, and nigellidine are indazoles. Nigellicine was isolated from the widely distributed plant Nigella sativa L. (black cumin). Nigeglanine was isolated from extracts of Nigella glandulifera.

The Davis–Beirut reaction can generate 2H-indazoles.

Indazole, C7H6N2, was obtained by E. Fischer (Ann. 1883, 221,p. 280) by heating ortho-hydrazine cinnamic acid,[3]

Drugs made from Indazole

Marsanidine [1034875-38-1][4][5]

Some derivatives

indazole-3-carboxylic acid
Having a carboxylic acid group on carbon 3. Can be further modified to lonidamine.

See also

References

  • Synthesis: Stadlbauer, W. (2002). "Product Class 2: 1H- and 2H-Indazoles". In Neier; Bellus (eds.). Category 2, Hetarenes and Related Ring Systems. Science of Synthesis. Houben-Weyl. doi:10.1055/sos-SD-012-00277. ISBN 9783131122711.
  • Review: Schmidt, Andreas; Beutler, Ariane; Snovydovych, Bohdan (2008). "Recent Advances in the Chemistry of Indazoles". European Journal of Organic Chemistry. 2008 (24): 4073–4095. doi:10.1002/ejoc.200800227.