Dual SNAr reaction in activated ortho-halonitrobenzene: direct synthesis of substituted 1,2,3,4-tetrahydroquinoxalines, 2,3-dihydro-1,4-benzoxazines, and 1,4-benzodioxines†
Abstract
An unprecedented one-pot synthesis of substituted 1,2,3,4-tetrahydroquinoxalines, 2,3-dihydro-1,4-benzoxazines, and 1,4-benzodioxines from activated ortho-halonitrobenzenes has been accomplished by dual nucleophilic aromatic substitution (SNAr) of halogen followed by substitution of the nitro group by secondary diamines, secondary amino alcohols, and diols respectively.