What is "pyrazole"

n. 1 (context organic compound English) A heterocyclic organic compound containing two nitrogen atoms next to each others in a five-membered ring, called ''1,2-diazole'' in http://en.wikipedia.org/wiki/IUPAC%20nomenclature. 2 (context organic compound English) A group of compounds containing that structure.

Pyrazole is an organic compound with the formula CHNH. It is a heterocycle characterized by a 5-membered ring of three carbon atoms and two adjacent nitrogen atoms. Pyrazole is a weak base, with pK 11.5 (pK of the conjugated acid 2.49 at 25 °C). Pyrazoles are also a class of compounds that have the ring CN with adjacent nitrogen atoms. A notable drug containing a pyrazole ring is celecoxib (Celebrex).