Study of the influence of N-alkylation of 2-benzylthiopyrimidines on the growth of two bacteria of medical interest

The present work highlights the synthesis and effect of introducing substituents on the nitrogen at position -1 of five 2-benzylthiopyrimidine derivatives (6a-e). The compounds (6a-e) were obtained by condensation of 2-thiopyrimidines (4) with benzyl halides in the presence of a base. As for the N-alkylated/arylated-2thiobenzylpyrimidines (8a-k), they were obtained by nucleophilic substitution reaction on nitrogen in basic medium. All the synthesized compounds were characterized by 1H proton, 13C carbon NMR spectroscopic analyses and high resolution mass spectrometry. All compounds were subjected to antibacterial testing on two multidrug resistant strains of Escherichia coli and Staphylococcus aureus. The results revealed that compounds 6a, 6b, 6c, 6d and 6e showed no minimum inhibitory concentration on either E. coli or S. aureus. However, compounds 8b, 8c, 8d and 8f showed a MIC on S. aureus1174. As for the bacterial strain E. coli 1178, only compound 8h showed a minimum inhibitory concentration. N-alkylation/arylation enhanced the antibacterial effect of some 2-benzylthiopyrimidine derivatives.