Pannala Padmaja, Pedavenkatagari Narayana Reddy* and Bijaya Ketan Sahoo Pages 209 - 214 ( 6 )
2-Amino-4,5-dihydro-3-furancarbonitriles (ADFCs) have attracted much attention due to their utility as valuable synthetic intermediates for the preparation of a series of acyclic and cyclic organic compounds. On the other hand, indoles substituted with furans are highly interesting compounds displaying a wide range of biological and pharmaceutical activities. However, to the best of our knowledge, indole substituted 2-amino-4,5-dihydro-3-furancarbonitriles have not been previously reported. A new and efficient synthesis of indole substituted 2-amino-4,5-dihydro-3-furancarbonitriles has been developed in two steps using water as a solvent. The first step of the sequence involves threecomponent reaction of phenylglyoxals, indoles and malononitrile under aqueous and catalyst-free conditions for the synthesis of indole substituted β,β-dicyanoketones. Reduction of the obtained β,β- dicyanoketones with sodium borohydride in water at room temperature afforded the indole substituted 2-amino-4,5-dihydro-3-furancarbonitriles in good yields. Several substituted phenylglyooxals were reacted smoothly with indole or 2-methylindole and malononitrile to give the corresponding indole substituted β,β-dicyanoketones in good yields. Treatment of the obtained β,β-dicyanoketones with sodium borohydride in water furnished exclusively the indole substituted 2-amino-4,5-dihydro-3- furancarbonitriles in good yields. We have developed an efficient straightforward access to indole substituted β,β-dicyanoketones by one-pot three-component reaction of phenylglyoxals, indoles and malononitrile. The synthetic utility of obtained indole substituted β,β-dicyanoketones has been outlined by the preparation of indole substituted 2-amino-4,5-dihydro-3-furancarbonitriles. The advantage of catalyst-free, atom-economical and environmental benignity render it promising methods for preparation of indole substituted 2-amino-4,5-dihydro-3-furancarbonitriles.
2-Amino-4, 5-dihydro-3-furancarbonitriles, β, β-dicyanoketones, indoles, phenylglyoxals, malononitrile, organic compound.
Centre for Chemical Sciences and Technology, IST, Jawaharlal Nehru Technological University, Hyderabad, Telangana- 500085, Department of Chemistry, School of Technology, Gitam University, Telangana-502 102, Department of Chemistry, School of Technology, Gitam University, Telangana-502 102