by karan shende b pharm datta meghe collage of pharmacy

1. • Introduction: pyrrole
• Physical properties
• Chemical properties
• Synthesis of pyrrole
• reactions of pyrole
•medicinal uses

2.  It is a colourless volatile liquid.
 It’s boiling point is 131°C and melting point is -
23°C.
 It turns brown in the air and gradually resinifies.
 Only slightly soluble in water but it is totally
miscible with ether and ethanol.
 Pyrrole is weakly basic in nature.
 Pyrrole has a relatively high boiling point as
compared to furan and thiophene, this is due to
the presence of intermolecular hydrogen bonding
in pyrrole. vwa

3.  Pyrrole is aromatic and more reactive than
benzene.
 It gives electrophilic substitution reactions
such as halogenation , nitration ,etc.
 It also undergoes diazotization and
Reimer-Tiemann reactions, while benzene
does not.

4.  From furan
 By heating a mixture of furan, ammonia and
steam over alumina catalyst .

5.  It is a condensation reaction between 1,4-
dicarbonyl compound with ammonia or a primary
amine to form a substituted pyrrole. Pyrrole itself is
formed from succinaldehyde and ammonia.

7.  The hantzsh pyrrole synthesis is the reaction of
beta-ketoester with ammonia (or primary amine)
and alpha-haloketones to give substituted pyrrole.

9.  Pyrrole is obtained by the distillation of
succinimide with zinc dust.

10.  Pyrrole is obtained by passing acetylene and
ammonia through a red hot tube.
acetylene Ammonia

11.  Acylation
 Pyrrole treated with acetic anhydride at 200°C gives
2 – acetyl pyrrole while N – acetyl pyrrole can be
obtained by heating pyrrole with N –
acetylimidazole.

12.  Pyrrole is oxidized to maleinimide and on reduction
it gives pyrrolidine.

13.  When potassium pyrrole is heated with chloroform
and sodium ethoxide, the pyrrole (five – membered
ring) expands to pyridine (six-membered ring).

14.  In the presence of a strong base and chloroform,
pyrrole undergoes Reimer – Tiemann reaction to
form pyrrole – 2 – aldehyde.

15.  Pyrrole may be formylated by heating it with
phosphorus oxychloride and dimethyl formamide.
The intermediate is hydrolyzed in the presence of a
mild base to 2 – pyrrole carbaldehyde.

16.  Electrophilic substitution:
The electrophilic substitution takes place preferably
at C2 or C5 – positions. If these positions are
already occupied then substitution takes place at
C3 or C4 positions.
1.Nitration
2.Sulphonation
3.Friedal craft alkylation
4.Friedal craft acylation
5.halogenation

18. 2-nitropyrrole 3-nitropyrrole
Reaction:nitration of pyrrole results in 2 product .one is major product and
second is minor product………

19. Reaction:pyrrole is reacted with sulphuric acid in the presence of sulphuric
acid and it gives two product one is major product and one is minor
product.
2-pyrrole sulfonic
acid
3-pyrrole sulfonic
acid

20.  Reaction:pyrrole is reacted with CL2 in the presence
of ALCL3 and it gives two product one is major
product and one is minor product.
pyrrole
cl2
ALCL3
2-chloropyrrole 3-chloropyrrole

21. Reaction:pyrrole is reacted with alkyl group
in the presence of ALCL3 and it gives two
product one is major product and one is
minor product.
pyrrole 2-methylpyrrole 3-methylpyrrole
CH3-I
ALCL3

22. Reaction:pyrrole is reacted with acyl group in the
presence of ALCL3 and it gives two product one is
major product and one is minor product.
pyrrole
ch3cocl
alcl3
2-ethylpyrrole 3-ethyl pyrrole

23.  Used in narcotic industry for making tabbaco.
 Used in cardiac disease medicine .
 Used in making pyrole derivatives.
 Anti-bacterial.
 Anti-psycotic.
 Anti-malerial.
 Anti-cancer.
 Anti-muscarinic drug to treat parkinsonism.
 Anti-fungal

24.  Pyrrole itself is completely planar and have molecular
dimensions.
 The 5 Sp2 hybridised C-atom sustained 6π electron
system. From the molecular orbital standpoint is
consisting of planar pentagoan with Sp2 hybridised C-
atoms.
 Each of the 4 C-atoms has one electron remaning in a
pz orbital. The N-atom has 2 electron in p orbital.
 These p orbitals overlap to give a total of six electrons
in π system and this shell provide stability.
 Pyrrole is an extremely weak base because its pair of
non-bonding electrons are part of the π-cloud (Kb =
2.5 x 10-14). Therefore, if pyrrole is protonated, it
loses its aromaticity.