Indazole

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

Quick facts Names, Identifiers ...

Indazole

Names
Preferred IUPAC name 1H-Indazole[1]
Identifiers
CAS Number	271-44-3 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:36670 Y
ChEMBL	ChEMBL86795 Y
ChemSpider	8866 Y
ECHA InfoCard	100.005.436
PubChem CID	9221
UNII	7C4VQE5C03 Y
CompTox Dashboard (EPA)	DTXSID4075374
InChI InChI=1S/C7H6N2/c1-2-4-7-6(3-1)5-8-9-7/h1-5H,(H,8,9) Y Key: BAXOFTOLAUCFNW-UHFFFAOYSA-N Y InChI=1/C7H6N2/c1-2-4-7-6(3-1)5-8-9-7/h1-5H,(H,8,9) Key: BAXOFTOLAUCFNW-UHFFFAOYAQ
SMILES c2ccc1[nH]ncc1c2
Properties
Chemical formula	C7H6N2
Molar mass	118.14 g/mol
Melting point	147 to 149 °C (297 to 300 °F; 420 to 422 K)
Boiling point	270 °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). Infobox references

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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.^[3]

Indazole, C₇H₆N₂, was obtained by E. Fischer (Ann. 1883, 221, p. 280) by heating ortho-hydrazine cinnamic acid,^[4]