Bis-dispiro-indolinone-pyrrolidine-imidazolones with polymethylene linkers between imidazolone fragments

Abstract

A method for the synthesis of bis-(dispiro-imidazolone-pyrrolidine-indolinones) in which spirocyclic fragments are linked by C4, C6 and C8 alkyl linkers between the N(3) nitrogen atoms of the imidazolone ring has been proposed. A two-step synthetic sequence was used for the synthesis, consisting of the interaction of α,ω-dialkylamines with ethyl isothiocyanatoacetate, followed by the reaction of the intermediate bis-thioureas with substituted benzaldehydes to produce bis-arylidenetiohydantoins and the final 1,3-dipolar cycloaddition of azomethine ylides generated in situ from isatins and N-methylglycine.