Synthesis and chemical transformations of 6-(morpholine-4-sulfonyl)-quinoline-2,3,4-tricarboxylic acid

The article describes an effective synthesis and chemical transformations of 6-( morpholine-4-sulfonyl)-2,3,4-quinolinetricarboxylic acid. The key step is the Pfitzinger reaction of 3,3-dichloro-2-oxo-2,3-dihydro-1H-indole with diethyl 2-oxo-succinate. Selective 2-decarboxylation of the tricarboxylic acid followed by reaction of the resulting anhydride with a primary amine led to the formation of the 1,3-dioxo-2,3-dihydro-1H-pyrrolo[3,4-c]quinoline scaffold with interesting pharmacological activity.