Synthesis of Novel Spiro[chromene-4,3'-indolines] and Spiro(indoline-3,4'-pyrano[3,2-h]quinolines)

The condensation of 1-alkylisatines with malononitrile and 8-hydroxyquinoline or 5,5-dimethyl-cyclohexane-1,3-dione in the presence of an aqueous solution of trimethylamine proceeds regioselectively as a one-pot three-component domino process to form spiro[chromene-4,3'-indoline] and spiro(indoline-3,4'-pyrano[3,2-h]quinoline).