Imidazole & it's preparation

1. BENGAL SCHOOL OF TECHNOLOGY
– PHARMACEUTICAL ORGANIC CHEMISTRY III
– PT - 414
– IMIDAZOLE

2. IMIDAZOLE
– INTRODUCTION:- Imidazole is an organic compound with the formula
C3N2H4. It is a white colour less solid that is soluble in water, producing a
mildly alkaline solution. In Chemistry it is an aromatic hetero cycle, classified
as a diazole and has non-adjacent nitrogen atoms.

3. PROPERTIES
PHYSICAL PROPERTIES:- Imidazole is a white
or colourless solid. it can show a prisamatic
crystal apperence. imidazole is highly soluble in
water, ethanol, ethyl ether and chloroform and its
soluble in non polar solvents. In water it
produces an alkaline solution. Its melting point is
88- 91o C and its boiling point is 256oC.

4. PROPERTIES
– CHEMICAL PROPERTIES:- Imidazole is a 5-Membere rings that show two
tautomeric structures due to the positive charge can be located in both of the
nitrogen atom, thus the hydrogen binds to the nitrogen atom can be removed
easily because the lesser electron density of nitrogen atom has an unshared
electron pair in a sp2 orbital that can accept protons consequently imidazole
shows an amproteric behavior. It can act as a weak base or a weak acid.

5. PREPARATION
– 1. By the action of glyoxal and ammonia.

6. PREPARATION
– 2. General method of preparation.
– 3. By Action of ammonia or mixture of HCHO and tartaric acid
Di-nitrate and then Heating the corresponding Di- Carboxilic
Acid.

7. REACTIONS
– Imidazole is a weak base but more basic than pyrazole it is a tautomeric
substance because position 4 & 5 are equivalent.
1. Imidazole reacts with methyl iodide in KOH solution to form 1- ,ethyl imidazole
which when heated strongly converts to 2- methyl imidazole.

8. REACTIONS
– HYDROGENATION:-
-ELECTROPHILIC SUBSTITUTION REACTION

9. – BENZIMIDAZOLE :- Benzimidazole is prepared by
condensing O - phenyle Di- amine and formic acid.
–

10. USE OF IMIDAZOLE
– Use :-
– .Used as raw material by the pharmaceutical industries for manufacturing anti
fungul drugs e.g Clotrimazole, Ketoconazole.
– Also used as pesticide & insectiside.
– It can bealso used as corrision inhibitor of metals such as copper.

11. THANK YOU