Synthesis of 2-monosubstituted-4-(2H)quinazolinones and 2,3-disubstituted-4-(3H)quinazolinones as antimicrobial agents

Abstract

The chemistry of quinazoline family of compounds including their preparations, reactions, properties together with a review of their most important biological activities were dealt with in chapter one. Thirteen final compounds were prepared in this work, together with their corresponding intermediates. The appropriate retrosynthetic analysis of the compounds revealed two possible routes for the target quinazolinones. The first route required a one step direct reaction between an amide and anthranilic acid, while the second approach involve a three step reaction. The three step reaction was achieved through acetylation of anthranilic acid followed by thermal cyclization to acetanthranil, the latter was then reacted with the desired amine to obtain the product. The two approaches were tried and result in the formation of the same products. The reaction course was followed with TLC and the identity of the products was identified through U.V, I.R, 1H-NMR and MS. The retrosynthetic analysis of the compounds was discussed in chapter three together with suitable mechanisms of each different reactions. The spectral data were interpretated and discussed in the same chapter. The final compounds were found to possess a weak antimicrobial activity when tested against five microorganisms, Pseudomonas, Klebsiella, Proteus, Staphylococcus aureus and Eschrichia coli.