Polyphosphoric Acid Esters Promoted Synthesis of Quinazolin-4(3)-imines from 2-Aminobenzonitrile.

A novel method for the synthesis of quinazolin-4(3)-imines (QIs) by trimethylsilyl polyphosphate (PPSE) promoted reaction of 2-aminobenzonitrile with secondary amides is reported. The reaction is general and allows for the synthesis of -aryl and -alkyl QIs with variable 2-substituents affording high yields. The procedure was extended to derivatives bearing additional functional groups.