Ni–Al2O3 as reusable heterogeneous catalyst for expedient one-pot synthesis of naphthopyrans

• DOI: 10.1007/s11164-016-2500-4
• Publication Date: 2016-03-22T13:37:44Z
• Authors: Subarna Jyoti Kalita; Nilakhy Saikia; Dibakar Chandra Deka; Hormi Mecadon
• Keywords: One-pot synthesis; Component (thermodynamics)

Ni–Al2O3 is an efficient and reusable heterogeneous catalyst for the synthesis of naphthopyrans by one-pot three-component reaction of naphthols, aldehydes, and malononitrile in EtOH/H2O (1:1) solvent medium. A comparative study of Ni–Al2O3 with neutral Al2O3 revealed that reactions with the former afforded better product yields, indicating higher catalytic efficacy. Ni–Al2O3 due to its low cost, good activity, ease of handling, and easy recovery, with high yields and simple purification method makes the procedure highly applicable.