Kabachnik–Fields synthesis of novel 2-oxoindolin methyl phosphonate derivatives using CAN.

The work reports ultrasound promoted facile synthesis of novel ten α-aminophosphonate derivatives coupled with indole-2,3-dione moiety, namely diethyl(substituted phenyl/heteryl)(2-(2-oxoindolin-3ylidene)hydrazinyl)methylphosphonates derivatives 4(a-j). The derivatives 4(a-j) were synthesized through one-pot three component Kabachnik-Fields reaction, by stirring at room temperature in presence of Cerric Ammonium Nitrate (CAN) as a catalyst, to give the final compounds in better yields and in shorter reaction time. Isatin, chemically known as 1-H-indole-2,3-dione, and its derivatives possess a broad range of biological and pharmacological properties. Isatin is widely used as 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. The general low mammalian toxicity of these compounds made them attractive for use in agriculture and medicine. Considering the importance of the two pharmacophores, promoted us to club both the pharmacophores in a single molecule using 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.