Ultrasound Assisted Synthesis of Diethyl (2-(1-(morpholinomethyl)-2-Oxoindolin-3-ylidene)hydrazinyl) (Substituted Phenyl/heteryl) MethylphosphonateDerivatives ^†

This work reports ultrasound assisted synthesis diethyl (2-(1-(morpholinomethyl)-2-oxoindolin-3-ylidene)hydrazinyl) (substituted phenyl/heteryl) methylphosphonate 9(a–j) derivatives. The derivatives are synthesized using a green protocol. In the first step, 3-hydrazonoindolin-2-one is synthesized using ultrasound. In the second step, diethyl (substituted phenyl/heteryl)(2-(2-oxoindolin-3-ylidene)hydrazinyl) methylphosphonate 6(a–j) derivatives are synthesized using cerric ammonium nitrate as catalyst. In the third step, diethyl (2-(1-(morpholinomethyl)-2-oxoindolin-3-ylidene)hydrazinyl) (substituted phenyl/heteryl) methylphosphonate 9(a–j) derivatives are synthesized using ultrasound. Isatin, chemically known as H-indole-2,3-dione, and its derivatives possess a broad range of biological and pharmacological properties. Isatin is widely used as a starting material for the synthesis of a broad range of heterocyclic compounds and as substrates for drug synthesis. The α-amino phosphonate derivatives constitute an important class of organophosphorus compounds on account of their versatile biological activity. Morpholine moiety has been found to be an eminent pharmacophore in medicinal chemistry. A number of molecules possessing morpholine moiety are clinically approved drugs. The importance of this ring is well understood by medicinal chemists, since they play a major role in molecular properties such as an electronic distribution, three dimensionality, scaffold flexibility/rigidity, lipophilicity or polarity and metabolic stability. Considering the importance of the three pharmacophores, this promoted us to club these pharmacophores together in a single molecule using a green synthetic protocol.The structures of the ultrasound synthesized compounds were confirmed by spectral analysis like IR, 1H NMR, 13C NMR, 31P NMR and MS.