Synthesis of Novel Quinazoline Derivatives as Antimicrobial Agents

Quinazoline isothiocyanate 1 reacts with various nucleophiles (nitrogen nucleophiles, oxygen nucleophiles and sulphur nucleophiles) to afford heterocyclic systemes 2–13. Also, the [4 + 2] cycloaddition reaction of 1 with phenyl isocyanate, benzylidene aryl amine and cinnamic acid derivatives gave novel heterocyclic compounds 14–16. Moreover, the reaction of 1 with active methylene compounds under Michael reaction conditions also was investigated to yield 17 and 18 and it was found that all these reactions proceeded via isothiocyanate heterocyclization to furnish non‐condensed heterocyclic compounds. Some of the newly synthesized compounds were tested for their antimicrobial activities.