2. Two thirds of all organic compounds are aromatic
heterocycles.
Most pharmaceuticals are heterocycles.
Definition Of Heterocyclic Compounds:
Heterocyclic compounds are cyclic compounds which contains
one/more atoms of other elements along with carbon atoms.
Definition Of Heteroatom:
Hetero atoms are those which contains an atom other than
carbon such as nitrogen, sulphur, oxygen, phosphorus etc.
3.
4.
5. •Many heterocyclic compounds are biosynthesized by plants
and animals and are biologically active.
• Some heterocycles are fundamental to life, such as haem
derivatives in blood and the chlorophylls essential for
photosynthesis.
•Similarly, the paired bases found in RNA and DNA are
heterocycles
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12. NOMENCLATURE
• Systematic nomenclature system is used for naming 3-10
membered monocyclic heterocyclics of various degree of the
unstauration containing one/more heteroatoms.
• It specifies the following characters such as:
- the ring size
- the nature
- the type of heteroatom
- the position of heteroatom etc.
• These hetrocompounds are also comply with the general rule
that is proposed by the “Huckel Rule ”
“Huckel rule” states that aromaticity is obtained in the cyclic
conjugated and planer system containing (4n+2) π electrons.
13. The heterocyclic compounds are named by fusing the following
rules:
1- Combination of prefixes with stem
2- The prefixes for different heteroatoms.
3- stem may be divided into two subdivided:
a) Basic term represent of ring size.
b) Suffixes represent of the end term
