Green Preparation and Structure Elucidation of Spiro Indole Derivatives Using Grindstone Technique

Abstract

Grindstone Chemistry technique or Toda’s solvent-free green method of grinding reactants together has been successfully applied for conducting multicomponent reaction of 1H-indole-2,3-dione, malononitrile and 2-thioxo-4-thiazolidinone for the synthesis of Spiro indole derivatives. The reaction conditions have been studied and compared with conventional methods in terms of reaction time, yield and workup procedure. Grinding takes only 15 minutes to complete the reaction. The synthesized compounds have been characterized by IR, 1HNMR, and 13CNMR spectra.