A green, facile and recyclable Mn3O4/MWCNT nano-catalyst for the synthesis of quinolines via one-pot multicomponent reactions

An efficient three‐component condensation reaction of aromatic aldehydes, 1,3-cyclohexanedione and 5-amino-3-methyl-1-phenylpyrazole in the presence of 2.5% Mn doped MWCNT nanoparticles as a heterogeneous, eco-friendly, recyclable and competent catalyst provided the subsequent quinoline derivatives in excellent yields (92–98%) under green solvent condition in very short reaction times. The prepared catalyst was characterized using different analytical techniques such as PXRD, N2 adsorption–desorption, FESEM, EDX and TEM. This protocol deals various benefits such as simple operation, easy handling, inexpensive, short reaction times, absence of toxic solvents, excellent yields, and avoidance of tedious workup. Additionally, the catalyst is easily separated and reused up to eight cycles without any significant loss of catalytic activity.