A series of N-Mannich bases of benzimidazolyl substituted 1H-isoindole-1,3(2H) dione have been derived by the reaction of different substituted amino acids with phthalic anhydride to yield 2-(substituted) 1H-isoindole-1,3(2H) diones (3), further condensation with o-phenylenediamine yields 2substituted benzimidazolyl 1H-isoindole-1,3(2H) diones (4), followed mannich reaction with methanal and different amines to yields final products (5). The chemical structures of synthesized N-Mannich bases were determined by elemental analysis and spectral data (FTIR & 1 H NMR). All the synthesized derivatives have been evaluated for their antimicrobial, anthelmintic and insecticidal activities against microbes, helminthes and insects selected as compared to standard drugs by using disc diffusion method and Watkins technique respectively. All the synthesized N-Mannich bases possess the significant antimicrobial, anthelmintic and insecticidal activities.

A new series of 4(4'-bromophenyl)-6-substituted aryl-1-acetyl pyrimidine-2-thiol derivatives were synthesized by heating chalcones with thiourea, in the presence of ethanolic potassium hydroxide, followed by treatment with acetyl chloride. The structure of the compounds was characterized by IR and H1NMR spectral study and elemental analysis. The compounds were screened for their antimicrobial, anthelmintic and insecticidal activities. All the compounds exhibited significant to moderate biological activities.