A simple entry to novel spiro dihydroquinoline-oxindoles using Povarov reaction between 3-N-aryliminoisatins and isoeugenol

An easy, fast, and cheap way for the synthesis of the new 4′-(4-hydroxy-3-methoxyphenyl)-3′-methyl-3′,4′-dihydro-1′H-spiro[indoline-3,2′-quinolin]-2-ones using BF3 OEt2-promoted imino Diels–Alder cycloaddition between ketimine-isatin derivatives and trans-isoeugenol.