One-pot synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives under solvent-free conditions

Abstract

A series of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones were obtained from aldehydes, phthalhydrazide and malononitrile in good to excellent yields at 80–100 °C under solvent-free conditions by proceeding through a simple, mild and efficient procedure utilizing N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide [TBBDA] and poly(N-bromo-N-ethylbenzene-1,3-disulfonamide) [PBBS] as catalysts.