1, 4-Diazabicyclo[2.2.2]octanium diacetate catalyzed synthesis of chromenes

Chromene and its derivatives belong to a major class of natural heterocyclic compounds, which they occur widely in edible vegetables and fruits. They frequently expose a variety of biological and pharmacological activities. Based on the extensive researches, it has been observed that chromene derivatives include biological activities such as antioxidant, spamolytic, anti-HIV, anticancer, anti-anaphylactic, antibacterial activity antihypertensive, anti-tubulin, antiviral, activator of potassium channels and inhibition of phosphodiesterase IV or dihydrofolate reductase, etc [1-2]. Several methods have been reported for the synthesis of 2-amino-4H-chromene derivatives using malononitrile, resorcinol and aldehyde. Various catalysts such as piperidine, cetyltrimethylammonium bromide (CTABr) , TFE , Ca(OH)2 , MgAl/HT and tungstic acid functionalized mesoporous SBA-15 have been used for these reactions. However, many of these methods suffer from acidic media, unsatisfactory yields, longer reaction times, difficult work up, excessive use of reagents and catalyst. It is therefore, important to find more convenient methods for the preparation of these compounds. In order to make the reaction simple and green and in continuation of our efforts for the synthesis of heterocyclic compounds [3], herein, 1, 4-Diazabicyclo[2.2.2]octanium diacetatehas been successfully applied to perform the reaction of B-naphtol, malononitrile and arylaldehyde to provide a series of chromene derivatives in excellent yields and short reaction times.