Synthesis of pyranopyrazole using nano triethanolammonium trichloroacetate

Pyranopyrazole derivatives are important class of hetrocycles due to their wide range of biological and pharmaceutical properties. In addition to fungicidal, bactericidal and herbicidal activities they also exhibit analgesic and anti-flammatory activities and act as hypotensive, hypoglycemic agent vasodilators[1]. Ionic liquids are salts that are liquid at low temperature ( 100 degrees C) which represent a new class of solvents with nonmolecular, ionic character. Although ionic liquids have only been studied in depth during the last decades, the field is now maturing to such a degree that the focus is on larger scale applications for use in real processes such as catalysis [2].Herein, we wish to present a green procedure for the synthesis of pyranopyrazole via three component reaction of 3-methyl 5-pyrazolon, malononitrile and various aromatic aldehydes in ethanol at 85 ˚C using nano triethanolammonium trichloroacetate[TEATCA].This method offers several advantages such as inexpensive catalysts, mild reaction conditions and operational simplicity.