One-pot, four-component synthesis of new 3,4,7,8-tetrahydro-3,3-dimethyl-11-aryl-2H-pyridazino[1,2-a]indazole-1,6,9(11H)-triones and 2H-indazolo[2,1-b]phthalazine-1,6,11(13H)-triones using an acidic ionic liquid N,N-diethyl-N-sulfoethanammonium chloride ([Et3N-SO3H]Cl) as a highly efficient and recyclable catalyst

A rapid and efficient one-pot, four-component protocol for the synthesis of novel 2H-pyridazino[1,2-a]indazole-1,6,9(11H)-triones (6) and 2H-indazolo[2,1-b]phthalazine-1,6,11-triones (7) has been developed using a stable and reusable Bronsted acidic ionic liquid N,N-diethyl-N-sulfoethanammonium chloride ([Et3N-SO3H]Cl). A range of diverse aldehydes were successfully applied and the corresponding products obtained in good to excellent yields without any by-products. (C) 2016 Elsevier Ltd. All rights reserved.