Pyrazole

Pyrazole
Names
	Preferred IUPAC name 1H-Pyrazole
	Systematic IUPAC name 1,2-Diazacyclopenta-2,4-diene
	Other names 1,2-Diazole
Identifiers
CAS Number	288-13-1 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	103775
ChEBI	CHEBI:17241 ;
ChEMBL	ChEMBL15967 ;
ChemSpider	1019 ;
DrugBank	DB02757 ;
ECHA InfoCard	100.005.471
EC Number	206-017-1;
Gmelin Reference	1360
KEGG	C00481 ;
PubChem CID	1048;
UNII	3QD5KJZ7ZJ ;
CompTox Dashboard (EPA)	DTXSID2059774 ;
	InChI InChI=1S/C3H4N2/c1-2-4-5-3-1/h1-3H,(H,4,5) Key: WTKZEGDFNFYCGP-UHFFFAOYSA-N ; InChI=1/C3H4N2/c1-2-4-5-3-1/h1-3H,(H,4,5) Key: WTKZEGDFNFYCGP-UHFFFAOYAW;
	SMILES c1cn[nH]c1;
Properties
Chemical formula	C3H4N2
Molar mass	68.079 g·mol−1
Melting point	66 to 70 °C (151 to 158 °F; 339 to 343 K)
Boiling point	186 to 188 °C (367 to 370 °F; 459 to 461 K)
Basicity (pKb)	11.5
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H302, H311, H315, H318, H319, H335, H372, H412
Precautionary statements	P260, P261, P262, P264, P264+P265, P270, P271, P273, P280, P301+P317, P302+P352, P304+P340, P305+P351+P338, P305+P354+P338, P316, P317, P319, P321, P330, P332+P317, P337+P317, P361+P364, P362+P364, P403+P233, P405, P501
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Pyrazole is an organic compound with the formula (CH)₃N₂H. It is a heterocycle characterized as an azole with a 5-membered ring of three carbon atoms and two adjacent nitrogen atoms, which are in ortho-substitution. Pyrazoles are also a class of compounds that have the ring C₃N₂ with adjacent nitrogen atoms. Pyrazole itself has few applications but many substituted pyrazoles are of commercial interest. Notable drugs containing a pyrazole ring are celecoxib (celebrex) and the anabolic steroid stanozolol.