Synthesis of some 11H-indeno[1,2-b]quinoxalin-11-ones

Article abstract of DOI:10.1016/S0040-4020(01)80184-8

Condensation of substituted o-phenylene diamines and ninhydrins gave the title compounds. The substituent orientation in the products was determined by ¹H NMR analysis of the chemical shifts brought about by N5-oxidation. Reduction of the 8-nitro to 8-amino compound was achieved both with and without reduction of the carbonyl group. Nitration of the 8-carboxylic acid occurred in the 2-position.