Facile Synthesis, Characterization of Novel Schiff Bases and N-Nucleosides Bearing Quinazoline Moiety and Evaluation Their Antimicrobial effects


The present work describes convenient synthesis of the novel Schiff bases 4, 5 and 6 by reaction of each of the previously synthesized quinazolinones 1, 2 and 3 with p-methoxybenzaldehyde. [2+2] Cycloaddition Reaction of the former Schiff bases within phenylisothiocyanate affording azatedine derivatives 7 and 8. Also, the quinazolines 1 and 2 could be reacted with α-bromoglucose tetraacetate giving peracetylated N-glycosides of quinazolinones 9 and 10 which were then deacetylated to afford N-glycosylated quinazolinones 11 and 12 respectively. On the other hand, Dapsone was reacted with p-methoxyacetophenone to afford 4-[(4-aminophenyl) sulfonyl]-N-[(1E)-1-(4-methoxyphenyl)ethylidene]aniline 15 which was, in turn, reacted with 4-chloro-2-ethoxyquinazoline 16 affording Schiff base 17. The latter was reacted with 2-furoyl chloride affording Schiff base 18. The structures of the novel Schiff bases and N-glycosides were confirmed by the IR, 1H-NMR, 13C-NMR, MS and elemental analysis. The antimicrobial activity for these synthesized compounds could outline, the moderate activity was observed with new quinazoline compounds which proved to possess marked activity against E. coli, S. aureus and C. albicans. The strong activity has observed nearly with the most synthesized compounds .