Abstract
Compound 1 condensed with benzaldehyde to produce styryl pyrimidine 2. Pyridopyrimidines 5, 8 and 10 resulted from [4 + 2] cycloaddition (condensation) of 1 with malononitrile, ethyl cyanoacetate and/or ethyl acetoacetate. Compound 1 was also concerted to pyridopyrimidine 14 through multistep reaction (hydrolysis, chlorination, isothiocyanate formation and intramolecular cyclization). Bromopyrimidine 15 transformed into thiazolopyrimidine 17. Cyclization of bromomethyl pyrimidine 15 resulted in imidazolopyrimidine 19. Upon reacting the compound 15 with ammonium acetate resulted in amination affording the amino derivative 20. Oxazolopyrimidine 21 was obtained as the result of the reaction of compound 1 with chloroacetic acid and p-nitrobenzaldehyde. Compound 21 was transformed into pyridopyrimidine 23 and pyridopyrimidine of type 25 when reacted with cyanoacetamide and/or phenylhydrazine, respectively. All of the tested compounds showed good microbial activity against pathogenic microorganisms especially pyridopyrimidine derivative 21.