Synthesis and Biological Activity Evaluation of Novel Fused Pyrimidine Heterocyclic Compounds

Abstract

A new series of heterocyclic compounds was prepared via the reaction of different substituted hydrazonoyl chlorides 22, 120 and 121 with substituted aminopyrimidines 122-124. The reaction produced in general a mixture of acyclic products 127, 132b, 136, 137, 139a, 139b, 139c and fused heterocyclic rings 129, 133a, 133b, 140a and 140b. The obtained acyclic adducts compounds 127, 132b, 139a, 139b and 139c are produced as a result of direct attack of the pyrimidine amino groups 122-124 at the electrophilic carbon of nitrilimine. In one particular case the acyclic product 136, 137 was obtained as a result of direct attack of the pyrimidine nitrogen at the electrophilic carbon of nitrilimine. The fused imidazopyrimidine derivatives 129, 133a, 133b, 140a and 140b are obtained as a result of the reaction of the dinucleophilic pyrimidine nitrogen and the amino group at the dielectrophilic carbons of nitrilimine. The obtained products were fully characterized and their chemical structures were confirmed by 1H-NMR, 13C-NMR, MS and HRMS. The structures of compounds 132b and 133b were further confirmed by x-ray. The biological activities of the obtained products were tested and evaluated against Gram-negative and Gram positive microorganisms. The Microbroth Dilution Method was used to evaluate the antibacterial activity and determination of MIC50 for all of the obtained products.