Aromatic Heterocyclic Compound

1. Bangabandhu Sheikh Mujibur Rahman
Science & Technology University
Md. Golam Rabbani
Student ID: 16PHR052
Department of Pharmacy
BSMRSTU
Heterocyclic
Compounds

3. Contents
Heterocyclic Compound
Classification of Heterocyclic Compound
 Quinoline
Preparation of Quinoline
Physical Properties of Quinoline
Chemical Properties of Quinoline
Pharmaceutical Uses of Quinoline
Isoquinoline
Preparation of Isoquinoline
Physical Properties of Isoquinoline
Chemical Properties of Isoquinoline
Pharmaceutical Uses of Isouinoline

4. Chemistry of Heterocyclic Compound
Heterocyclic compound:
Heterocyclic compounds are organic compound that
contain a ring structure containing atoms in addition to
carbon,(like-N, S or O), as the hetero atom. For example:
Pyridine Quinoline Isoquinoline

5. Quinoline
Quinoline is a heterocyclic aromatic organic
compound with the chemical formula C9H7N. It is a
colorless hygroscopic liquid with a strong odor.
Aged samples, especially if exposed to light,
become yellow and later brown.The official name
of quinoline is 1-Azanaphthalene.

6. Preparation of Quinoline
By Skraups Synthesis:Aniline and glycerol is heated in the
presence of sulfuric acid and a mild oxidizing agent, usually
nitrobenzene to produce quinoline.
By the Friedlander Synthesis: This involves the condensation of o-
aminobenzaldehyde with acetaldehyde in the presence of an alkali to produce
quinoline.

7. Quinoline is a colourless liquid, bp 238C, having a
disagreeable,pyridine-like odor.
It is soluble in water and completely miscible with
alcohol,ether and acetone.
Chemically, it gives all the reactions of pyridine
and electrophilic substitution reactions of the
benzene ring.
Physical Properties of Quinoline

8. Chemical Properties of Quinoline
Formation of Salts: Quinoline reacts with acids and alkyl
halides yeilding quaternary salts.
Nucleophilic Substitution Reactions: Quinoline readily gives
nucleophilic substitution reactions shown by pyridine.

9. Electrophilic Substitution Reactions:
It undergoes electrophilic substitution reactions
in the benzen ring and not in the more resistant
pyridine ring.The electrophile preferable attacks
position 8 and 5
Chemical Properties of Quinoline

10. Reduction: Quinoline is easily reduced to yield 1,2,3,4-
tetrahydroquinoline.
Oxidation: On vigorous oxidation with alkaline potassium
permanganate,it yields pyridine-2,3-dicarboxylic acid.
Chemical Properties of Quinoline

11.  Quinolone are the family of synthesized broad
spectrum antibiotics.
Quinolone, in comparison to other antibiotic
classes, have among the highest risk of causing
colonization with MRSA and Clostridium difficile
The majority of quinolones in clinical use belong
to the subset fluoroquinolone.
Pharmaceutical Uses of Quinoline

12. Isoquinoline is a colorless hygroscopic liquid at room
temperature with a penetrating, unpleasant
odor.Isoquinoline is a weak base, with a pKaof 5.14.It
protonates to form salts upon treatment with strong acids,
such as HCl. It forms adducts with Lewis acids, such as BF3.
Isoquinoline
Figure:Isoquinoline

13. Preparation of Isoquinoline
Form Cinnamaldehyd:
Cinnamaldehyde with hydroxylamine to form the
corresponding oxime.The oxime is then heated with
phosphorus pentoxide to yeild isoquinoline.

14. Preparation of Isoquinoline
 By the Bischler-Napieralski Synthesis:
2-phenylethylamine is first react with formyl chloride in the presence of a
base to form N-formyl_2-phenylethylamine. This amide is next heated
with phosphorus pentoxide in pyridine to give 3,4-dihydroisoquinoline
which on oxidation(dehydrogenation) with palladium or selenium yields
isoquinoline

15. Isoquinoline is a colorless solid (mp 26 c, bp 243) with
a smell like that of benzaldehyde.
It is volatile in steam, soluble in water and is soluble in
many organic solvents.
It turns yellow on normal storage.
Isoquinoline (pKa=5.14) is stronger base than
quinoline.
It forms stable salts with acid.
Physical Properties of Isoquinoline

16. Isoquinoline resembles quinoline in most of its
chemical properties, like quinoline. it undergoes
electrophilic substitution at c-5 andC-8. It is oxidized by
alkaline potassium permanganate to give pyridine-3,4-
dicarboxylic acid (Cinchomeronic acid).
Chemical Properties of Isoquinoline

17. Bileducts and ureter and for use as a cerebral
and coronary vasodilator in subarachnoid-
hemorrhage (combined with balloon
angioplasty) and coronary artery bypass surgery .
As an erectile dysfunction drug alone or sometimes
incombination, hypertension, congestive-heart-failure
vasoconstrictor, angiotensin converting enzyme.
Used as anesthetic.
Pharmaceutical uses of Isoquinoline