Synthesis of 4-(N-alkyl-N-heteroaryl)amino-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-1-benzopyran-6-carbonitrile derivatives via an unusual 1,4-oxygen to nitrogen heteroaryl migration

Abstract Various heteroaryls were found to undergo 1,4-oxygen to nitrogen migration (e.g. 4→1 ) under acidic conditions. This unprecedented migratin provides a convenient access to 4-(N-alkyl-N-heteroaryl)amino-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-1-benzopyran-6-carbonitrile derivatives, which are otherwise difficult to prepare.