, a pyrazole-derived analgesic In 1959, the first natural pyrazole,
1-pyrazolyl-alanine, was isolated from seeds of
watermelons. In medicine, derivatives of pyrazole are widely used, including
celecoxib and similar
COX-2 inhibitors,
zaleplon,
betazole, and
CDPPB. The pyrazole ring is found within a variety of pesticides as fungicides, insecticides and herbicides,
fenpyroximate,
fipronil,
tebufenpyrad and
tolfenpyrad. Pyrazole moieties are listed among the highly used ring systems for small molecule drugs by the US FDA :
3-(Difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid is used in the manufacture of six commercial fungicides which are inhibitors of
succinate dehydrogenase. Pyrazole is an inhibitor of the
alcohol dehydrogenase enzyme, and, as such, is used as an adjuvant with ethanol, to induce alcohol dependency in experimental laboratory mice.
Conversion to scorpionates Pyrazoles react with
potassium borohydride to form a class of ligands known as
scorpionate. Pyrazole itself reacts with
potassium borohydride at high temperatures (~200 °C) to form a
tridentate ligand known as
Tp ligand: : ==See also==