Pyrazole

Pyrazole

Names
Preferred IUPAC name 1H-Pyrazole[1]
Systematic IUPAC name 1,2-Diazacyclopenta-2,4-diene
Other names 1,2-Diazole
Identifiers
CAS Number	288-13-1 Y
3D model (JSmol)	Interactive image
Beilstein Reference	103775
ChEBI	CHEBI:17241 Y
ChEMBL	ChEMBL15967 Y
ChemSpider	1019 Y
DrugBank	DB02757 Y
ECHA InfoCard	100.005.471
EC Number	206-017-1
Gmelin Reference	1360
KEGG	C00481 Y
PubChem CID	1048
UNII	3QD5KJZ7ZJ Y
CompTox Dashboard (EPA)	DTXSID2059774
InChI InChI=1S/C3H4N2/c1-2-4-5-3-1/h1-3H,(H,4,5) Y Key: WTKZEGDFNFYCGP-UHFFFAOYSA-N Y 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:[2]
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). Y verify (what is YN ?) 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. Pyrazole itself has few applications but many substituted pyrazoles are of commercial interest.