2. Pyrazole
Pyrazole is the name given by LUDWIG
KNORR to this class of compounds in 1883.
The simple doubly unsaturated compound
containing two nitrogen and three carbon
atoms in the ring, with the nitrogen atoms
neighboring, is known as pyrazole.
3. History
For a long time no pyrazole derivative had
been found in nature, but in 1959 硫-(1-
pyrazolyl) alanine was isolated from the seeds
of water melons (Citurllus lanatus) (L.
Fowden).
4. 3-n-nonylpyrazole is the first natural pyrazole
thta has been obtained from a plant
Houttuynia cordata which belongs to the
family Piperaceae. This compounds exhibit
anti-microbial property
6. Physical properties
Crystalline solid
Pyridine like odour
Bitter taste
Melting point 70属C
Boiling point 187属C
Soluble in water and organic solvents.
25. Sulfaphenazole : Sulphonamide antibiotic.
Used for treating cough and allergy
Celecoxib : NSAID . Used to treat arthritis,
pain, menstrual cramps, and colonic polyps.