Generality and scope of the synthesis of 2-arylpyrrolo[3,4-b] quinoxaline-1,3-diones from 2,3-dichloro-N-arylmaleimides. II

Article abstract of DOI:10.3987/COM-99-8716

Nucleophilic substitution of 2,3-dichloro-N-arylmaleimides (1) and (2) with a series of arylamines gives 2-arylamino-3-chloro-N-arylmaleimides (3) and (4), respectively. When 4 is treated with sodium azide at room temperature, it cyclizes to the 2-(p-methoxyphenyl)pyrrolo[3,4-b]quinoxaline- 1,3-diones (5). Under the same conditions, the 2-(p-nitrophenyl) analogue (3) fails to cyclize. Ring closure is also subject to the steric and electronic effects of substituents in the nucleophile.