Ultrasound-promoted Kabachnik–Fields Synthesis and Docking Studies of Novel Coupled Chromonyl-thiadiazolyl Derivatives.

The work reports facile green protocol for synthesis of novel ten derivatives of diethyl ((4-oxo-4H-chromen-3-yl)((5-sustituted phenyl-1,3,4-thiadiazol-2-yl)amino)methyl) phosphonate 6(a-j). The derivatives 6(a-j) were synthesized under ultrasound by coupling substituted thiadiazoles, α-aminophosphonate derivatives and 3-formyl chromone in a one-pot three component Kabachnik-Fields reaction, in presence of zirconium oxychloride (ZrOCl₂) as a catalyst, to give the final compounds in neat and clean protocol giving better yields in shorter reaction time. Thiadiazole and its derivatives possess a broad range of biological and pharmacological properties. 5-substituted phenyl-1,3,4-thiadiazol-2-amine is widely used as starting material for the synthesis of a broad range of heterocyclic compounds and as substrates for drug synthesis. 3-Formylchromone derivatives possess a broad range of biological and pharmacological properties. The α-amino phosphonate derivatives constitute an important class of organophosphorus compounds on account of their versatile biological activity. Nowadays, in medicinal chemistry molecular hybridization is an important strategy in planning drug synthesis. The important biological activities associated with these three moieties, namely, substituted thiadiazole, chromones and α-amino phosphonate derivatives promoted us to club these pharmacophores in a single molecule with the hope to get novel coupled derivatives with potent and enhanced biological activity.