A convenient approach for the synthesis of various derivatives of pyrazolo[1,2-b]phthalazinediones in the presence of an efficient supported basic ionic liquid at ambient temperature and solvent-free media

摘要

A convenient procedure has been described for one-pot synthesis of various pyrazolo[1,2-b]phthalazinediones at ambient temperature and solvent-free media. First, a novel supported basic ionic liquid ([SiPMIM]OH@MNPs) was prepared and characterized by FT-IR, elemental analysis, VSM, SEM, TEM and XRD. This catalyst exhibits excellent catalytic activity in one-pot reaction of aromatic aldehydes, phthalhydrazide and malononitrile (or acyclic 1,3-dicarbonyl compounds) to offer cyano-, acetyl- or benzoyl-substituted pyrazolo[1,2-b]phthalazinediones in high yields. Moreover, selective synthesis of mono- and bis-pyrazolo[1,2-b]phthalazinediones from dialdehydes was investigated in this approach. The catalyst could be easily separated by an external magnet and reused seven times without any significant loss of activity.