synthesized regioselectively in good to high yields by condensation of N,N-disubstituted thioureas and ethyl chloroacetate in the presence of basic ionicliquid [bmim]OH as a catalyst under conventional and ultrasonicirradiation conditions. Underultrasonicirradiation, the reaction furnished the desired 2-iminothiazolidinones in higher yields (76–87%) and lower reaction times (30–55 min). GRAPHICAL ABSTRACT
Facile synthesis of phthalidyl fused spiro thiohydantoins through silica sulfuric acid induced oxidative rearrangement of ninhydrin adducts of thioureas
作者:Subhro Mandal、Animesh Pramanik
DOI:10.1016/j.tet.2019.130817
日期:2020.1
A one-pot three-component sequential synthetic protocol produces structurally and biologically important phthalidyl fusedspiro N,N′-disubstituted thiohydantoins from readily available aromatic isothiocyanates, primary amines and ninhydrin. In this three-step synthesis while the initial two steps are catalyst-free, in the final step silica sulfuric acid (SSA) induces an oxidative rearrangement in [3