Synthesis of some new bis-Schiff bases of isatin and 5-fluoroisatin in a water suspension medium

Condensation of aromatic primary bis-amines with. isatin (IH-indole-2,3dione) and 5-flouroisatin occurred cleanly and efficiently in a water suspension medium without using any organic solvent or acid catalyst. The corresponding bis-Schiff bases were obtained in good yields and were easily isolated by filtration. Their structures were confirmed by H-1-NMR, C-13-NMR, IR and mass spectra.