Nanosized Aluminium Oxide as Catalyst for Rapid and Green Synthesis of 2-Amino-2-Chromenes

Organic transformations involving benign reaction media are of considerable interest in synthesis; especially multi component condensation (MCC) reactions in which two or more steps are completed without isolation of any intermediate [1]. The low cost of water, along with their non-toxic nature, renders them as attractive media for chemical synthesis and transformations. Heterogeneous catalysts are advantageous over conventional homogeneous catalysts as they can be easily recovered from the reaction mixture by simple filtration and can be reused after activation, thereby making the process economically viable. Among the heterogeneous basic catalyst, aluminium oxide is a versatile material used as catalyst for several base-catalyzed organic transformations[2], toxic waste remediation, and as additive in refractory, paint, and superconductor products[3]. Thus the synthesis of 2-amino-2-chromene is of much importance to organic chemists. We report herein our results with nanosized aluminium oxide the efficiently catalyzed three-component condensation of aldehyde, malononitrile, and α-naphtol in water as reaction media