|
Keywords
|
pyrazolo[1,2-b]phthalazines, ionic liquid, multicomponent reactions, solvent-free.
|
|
Abstract
|
A series of novel pyrazolo[1,2-b]phthalazine-2-carboxylate derivatives has been synthesized via one-pot four-component reaction of
aromatic aldehyde, ethyl or methyl acetoacetate, hydrazine hydrate, and phthalic anhydride in the presence of acidic ionic liquids such as
3-methyl-1-sulfo-1H-imidazol-3-ium chloride, 1,3-disulfo-1H-imidazol-3-ium chloride, and triethyl(sulfo)ammonium chloride as the
catalyst. This method involves particular advantages such as environmentally benign catalysts, high yields of product, reusability of ionic
liquids with high activity, short reaction times, no hazardous solvent, and easy workup.
|