Highly Efficient Cascade synthesis of Benzopyran

Highly Efficient Cascade synthesis of Benzopyran

1V. V. Borgaonkar,  2S. R. Pawar, *A. S. Patki

1,2Department of Chemistry, Shri Siddheshwar Mahavidyalaya Majalgaon, Dist. Beed

*Department of Chemistry, Shivaji Mahavidyalaya Renapur, Dist-Latur

Introduction:

Benzopyran is a polycyclic organic compound that results from the fusion of a benzene ring to a heterocyclic pyran ring. benzopyrans or chromenes, are key structural units of a variety of biologically important compounds, many of which are pharmaceutically significant unit of heterocyclic compounds.

Multicomponent reactions (MCRs) are highly efficient approaches to access complex structures in a simple synthetic operation from three or more reactants. High atom economy, great efficiency and procedural convenience in the construction of heterocycles are the advantages of MCRs [1-2].

Chemically, chromones (4H-chromen-4-ones) are heterocyclic compounds with the benzopyrone framework. Molecules containing the chromone or benzopyranone ring have a wide range of biological activities [3-6] such as antioxidant [7], anti-HIV [8, 9], neuroprotective [10], antiepileptic [11, 12], antimicrobial [13], antidiabetic [14], antihypertensive [15], and anticancer agents [16].

These compounds can be prepared by multicomponent condensation of dimedone with aldehyde and malononitrile in the presence of various catalysts including tetra-methyl ammonium hydroxide [17], iodine [18], NaBr [19], solid acids [20] ion-exchange resins [21] and metal complexes [22]. Development of a mild, neutral, and reusable catalyst for one-pot synthesis of benzopyrans still remains an attractive goal for researchers [23]. Some natural product that contains benzopyran scaffold were finds the application in drug and medicinal chemistry.