Dihetero double Michael addition in PEG-400: Synthesis of 2,3-dihydro- [2,3-c]-[1,2,4]-triazole scaffold

Abstract

Potassium carbonate in poly (ethylene glycol-400) has been found to be a highly effective and efficient medium for the straight forward, convenient, one pot and green synthesis of diethyl/ethyl cyano-5-[substituted phenyl-2,3-dihydro-[1,3,4]-thiadiazolidino - [2, 3-c] – [1, 2, 4]-triazol -2- yl] – malonate/acetate through intramolecular cyclo- elimination of Michael adducts formed between the reaction of 4-amino-5- substituted phenyl-3-mercapto-1,2,4-triazole 1 with diethyl-2-(ethoxymethylene) malonate and ethyl -2-cyano-3-ethoxyacrylate respectively. The structures of all the new compounds have been elucidated using IR, ¹H and ¹³C NMR, mass spectral data and elemental analyses.