Pyrimidine plays a very important role in many fields and here the physical and chemical properties are discussed along with Pinner pyrimidine synthesis mechanism and the synthesis of sulphamerazine and trimethoprim with its applicationS.

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2. INTRODUCTION:
HETEROCYCLIC COMPOUNDS:
Heterocyclic compounds are cyclic compounds with the ring containing carbon and other element, the component
being oxygen, nitrogen and sulfur.
SIX MEMBERED HETEROCYCLIC COMPOUNDS:
RING WITH ONE HETERO ATOM
RING WITH TWO HETERO ATOM
CONDENSED HETEROCYCLIC COMPOUNDS
PYRAN
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3. PYRIDAZINE PYRIMIDINE PYRAZINE
BASICITY:
Diazines are weaker bases when compared to pyridine due to the inductive and electron withdrawing
effect of 2nd nitrogen atom present in them.
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4. ELECTROPHILIC AND NUCLEOPHILIC SUBSTITUTION OF AZINES:
 PYRIDINE:
 PYRIDAZINE:
 PYRIMIDINE:
 PYRAZINE:
ELECTROPHILIC AROMATIC SUBS: C3 & C5
NUCLEOPHILIC SUBSTITUTION: C2, C4, C6.
ELECTROPHILIC AROMATIC SUBS: Difficult
NUCLEOPHILIC SUBSTITUTION: C3, C4, C5, C6.
ELECTROPHILIC AROMATIC SUBS: C5
NUCLEOPHILIC SUBSTITUTION: C2, C4, C6.
ELECTROPHILIC AROMATIC SUBS: C3
NUCLEOPHILIC SUBSTITUTION: C2
EAS is difficult in diazines due to the electron withdrawing nature of 2nd
nitrogen, hence the presence of electron donating groups like –NH2 is
necessary.
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5. PYRIMIDINE:
PHYSICAL PROPERTIES:
Pyrimidine is a colorless compound. It is a crystalline solid with melting point of 22°C which dissolves in water to give a
neutral solution and reacts with mineral acids to form salts.
MOLECULAR FORMULA:
C4H4N2
SYNONYMS:
1,3-Diazine,
Metadiazine,
1,3 Diazabenzene
PYRIMIDINE DERIVATIVES:
In nucleic acids, three types of nucleobases are pyrimidine derivatives: cytosine (C), thymine (T), and uracil (U).
USES:
The most important function of pyrimidines is in the construction of DNA and RNA. When paired with
purines, pyrimidines serve as the building blocks for DNA, which is the basis for the genes and chromosomes
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6. CHEMICAL PROPERTIES:
1. REACTION WITH ACIDS (PROTONATION):
2. N-ALKYLATION (QUATERNIZATION):
I-
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7. 3. ELECTROPHILIC AROMATIC SUBSTITUTION:
4. OXIDATION:
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8. 5. NUCLEOPHILIC SUBSTITUTION:
BASICITY:
Pyrimidine is less basic when compared to pyridine due to the 2nd nitrogen atom present in the ring which
has electron withdrawing effect.
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9. PYRIMIDINE SYNTHESIS:
PINNER PYRIMIDINE SYNTHESIS:
Acid or base catalyzed condensation reaction of 1,3 Dicarbonyl compounds with amidines or guanidines yield
pyrimidine derivatives is called as Pinner Pyrimidine synthesis.
Dicarbonyl
compound
Amidine
Pyrimidine
derivative
Acetylacetone Acetamidine
AcetamidineEthyl Acetoacetate
Sodium ethoxide
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10. MECHANISM:
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11. 2. REACTION WITH MALANOIC ESTER:
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12. 3. FROM 2,4 DICHLOROPYRIMIDINE:
4. FROM ALKYLPYRIMIDINE:
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13. PYRIMIDINE DERIVATIVES:
SULFAMERAZINE:
SULFAMERAZINE
SYNTHESIS:
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14. TRIMETHOPRIM:
Acetamidobenzene
sulfonylchloride
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15. TRIMETHOPRIM SYNTHESIS:
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16. PYRIMIDINE APPLICATIONS:
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17. PYRIMIDINE MOIETY – MEDICINAL USES:
 SULFAMERAZINE – ANTIBIOTIC
 TRIMETHOPRIM – TREATS UTI, PNEUMONIA
 PYRIMETHAMINE – ANTIPARASITE, MALARIA
 5 – FLUOROURACIL – TREATS COLON, BREAST, STOMACH, ESOPHAGEAL CANCER
 PHENOBARBITONE – SEDATIVE AND HYPNOTIC
 SULFADIAZINE – TREATS UTI
 ZIDOVIDINE – USED TO TREAT HIV INFECTION
 MINOXIDIL – VASODILATOR, TREATMENT OF HYPERTENSION
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