Synthesis, Characterization and Evaluation of Antibacterial Activity of Several New 1,8-naphthalimides Containing Benzothiazole Moiety

Abstract

A series of new 1,8-naphthalimides linked to benzothiazole moiety were synthesized by following two different strategies:The first one involved direct reaction of equimolar amounts of substituted-2-aminobenzothiazoles with 1,8-naphthalic anhydride in glacial acetic acid under reflux at high temperature for eight hours. The second strategy based on Gabrial synthesis including preparation of unsubstituted-1,8-naphthalimide via refluxing of naphthalic anhydride with ammonium hydroxide at high temperature for six hours then the resulted 1,8-naphthalimide was treated with alcoholic potassium hydroxide to afford naphthalimide potassium salt and this in turn was introduced in the reaction with 2-(2-chloroacetylamino)benzothiazoles (which were prepared via treatment of 2-aminobenzothazoles with chloroacetyl chloride) producing new series of N-(2-acetamido substituted benzothiazole-2-yl)-1,8-naphthalimides. Structures of the prepared compounds were confirmed by depending on FTIR, 1H-NMR and 13C NMR spectral data which were in agreement with the proposed ones. Finally antibacterial activity of some of the prepared new cyclic imides were evaluated against two types of bacteria and the results showed that the most of the tested imides posses good biological activity against these organisms.