Acid cyclization of amino-substituted heterocycles. Synthesis of 1,3-dioxo- pyrrolo[3,4-c]- and thieno[3,4-c]isoquino- lines and cinnolines

Article abstract of DOI:10.1007/s10593-009-0262-2

The reaction of 3-amino-4-(3,4-dimethoxyphenyl)maleimide and the methyl esters of 3-amino-4-(3,4-dimethoxyphenyl)-5-R-thiophene-2-carboxylic acids with carbonyl compounds and nitrous acid has been investigated. Dioxopyrrolo[3,4-c]- and thieno[3,4-c]isoqui