Synthesis of new unsymmetrical imidazolinium salts with mesityl and nitrophenyl suhstituents

摘要

An efficient five-step procedure for synthesis of unsymmetrical imidazolinium salts with mesityl and nitrophenyl substituents was elaborated. The starting nitroaniline was acylated with chloroacetyl chloride followed by Finkelstein displacement by iodide and coupling with mesitylamine. The key step was reduction of the amide carbonyl group with BH3·S(CH3)2. Finally, an imidazoline ring was constructed by reaction with trimethyl orthoformate. A different approach was attempted for 2,6-dinitroaniline, but final cyclization failed in this case.