Pseudo-Three-Component Spiro[dihydrofuran-2,3′-oxindoles] Synthesis: In Situ Generation of Diazooxindole.

Upon reaction with N-substituted pyrroloquinoxalinetriones, isatin hydrazone is oxidized to diazooxindole and enters into a formal [4+1] cycloaddition reaction with N-substituted pyrroloquinoxalinetriones to form compounds containing a spiro[dihydrofuran-2,3′-oxindole] fragment, which is interesting for medicinal chemistry. The reaction of diazooxindoles with N-unsubstituted pyrroloquinoxalinetriones afforded analogous substituted spiro[dihydrofuran-2,3′-oxindoles]. The resulting compounds show moderate antimicrobial activity. [ABSTRACT FROM AUTHOR]