Utility of Some Polyfunctional Substrates for the Synthesis of Novel Anticipated Biologically Active Diaza-, and/or Oxaza-, Heterocycles Integrated with a Heteryl Ring Moiety

Abstract

The first part of this thesis discusses the synthesis and some reactions of 4-(4-acetamidophenyl)-4-oxobut-2-enoic acid 1 and its aza Michael adduct 2. It also demonstrates the utility of these compounds to design novel heterocycles via reactions with various nitrogen and carbon nucleophiles. The former compound 1 was efficiently prepared from Friedel-Craft's reaction of acetanilide with maleic anhydride in the presence of anhydrous aluminum chloride (AlCl3). The latter derivatives 2 were synthesized via Michael addi-tion reaction type of benzimidazole, 2-methylbenzimidazole, benzylamine and p-anisidine on the acid 1 under different reaction conditions. Reaction of 1 with benzimidazole in pyridine went through nucleophilic addition on C-2, followed by decarboxylation under the effect of elevated temperature of boiling point of pyridine to afford N-(4-(3-(1H-benzo[d]imidazol-1-yl)propano-yl)phenyl)acetamide 2a. The structure of 2a was confirmed by a study of its spectral data including IR, 1H-NMR and Mass spectra. The target compounds 2b-e were successfully prepared by transfer the reaction to be carried out in other solvents, rather than pyridine. The employed solvents were dry benzene, dry toluene and ethanol, as well as, the nitrogen nucleophilic reagents used were benzimidazole, its 2-methyl derivative, benzylamine and p-anisidine. The reaction afforded the aza-Michael adduct 2b-e, respectively. The structure of the latter products were confirmed by spectral data involving IR, 1H-NMR and Mass spectra.