Pyrazole is a heterocyclic compound first named by Ludwig Knorr in 1883, characterized by a ring containing two nitrogen and three carbon atoms. Although naturally occurring derivatives were scarce, β-(1-pyrazolyl) alanine was isolated in 1959, and 3-n-nonylpyrazole was later found to have antimicrobial properties. Pyrazole derivatives, such as sulfaphenazole and celecoxib, are utilized in medicinal applications including treatment for infections, arthritis, and pain relief.

1. Hetrocyclic compound - Pyrazole
Lecture by
S.Mathivanan.,M.Pharm
Asst professor
Pharmacy

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 β-(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

5. Analogues of Pyrazole
Pyrazole Pyrazoline Pyrazolidine
5-Pyrazolinone 3,5-Pyrazolidinedione Imidazole (will discuss later)

6. Physical properties
• Crystalline solid
• Pyridine like odour
• Bitter taste
• Melting point 70°C
• Boiling point 187°C
• Soluble in water and organic solvents.

7. Chemical properties

10. Synthesis of Pyrazole

15. Reactions of Pyrazole

23. Medicinal uses of Pyrazole

25. • Sulfaphenazole : Sulphonamide antibiotic.
Used for treating cough and allergy
• Celecoxib : NSAID . Used to treat arthritis,
pain, menstrual cramps, and colonic polyps.

30. Thank you..!!!