الفهرس 
acknowledgmentOnly 14 pages are availabe for public view
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Abstract
Pyrimidine derivatives constitute an impartant class of compounds because they are components of the biologically important nucleic acids the have been shown to exert pronounced physiological effects for instance the replacement of naturally occurring prrimidine bases of the dna of microorganisms by unnatural analogous pyrimidines is attributed to the similarity in their steric properties.