Synthesis of some new spiro[indoline-3,2′-(1′,2′,3′,4′- tetrahydroquinoline)]-2,4′-dione derivatives

Article abstract of DOI:10.3987/com-97-7934

Indole-2,3-dione (1) was treated with malonic acid in a mixture of ethanol/pyridine to afford 3-(2-oxoindolinylidine)acetic acid (2), which then reacted with hydrobromic acid to yield 3-bromo-3-(2-oxoindole)acetic acid (3). Compound (3) reacted with aroma