HELVETICA CHIMICA ACTA, vol.94, no.5, pp.801-810, 2011 (SCI-Expanded)
Lactone analogues of 3-substituted oxindoles (= 1,3-dihydro-2H-indol-2-ones) and nonbenzoid oxa-analogous isoindigoid or nonbenzoid isoindigoid dyes were prepared by the reactions of furan-2,3-diones with oxindole and Lawesson reagent (Schemes 1 and 3), respectively. So, new derivatives of 2-oxobutanoic acid, bis-furanone, and bis-pyrrolone, which are potentially biologically active compounds, were synthesized for the first time.