Solvent-free synthesis of 1,2-dihydro-1-arylnaphtho[1,2-e] [1,3] oxazine-3-ones using a magnetic nickel–zinc ferrite nanocatalyst†

A high quality magnetic nanocatalyst Ni_0.5 Zn_0.5Fe₂O₄ (NZF) was synthesized via a sol–gel auto combustion method. The structure and morphology of the synthesized Ni_0.5Zn_0.5Fe₂O₄ (NZF) nanocatalyst were examined using various physico-chemical methods. The catalytic performance of the catalyst with varying transition metal composition was investigated for the solvent-free synthesis of 1,2-dihydro-1-arylnaphtho[1,2-e] [1,3] oxazine-3-ones, and it was found that the yield of the product was 87%. The NZF nanocatalyst showed excellent catalytic performance for a wide range of substrates with a very low catalyst loading. The super paramagnetic nature of the NZF nanocatalyst enabled the separation of the catalyst from the reaction mixture by magnetic recovery. Recyclability of the NZF nanocatalyst was also investigated, and it was found that the catalyst exhibited a recyclability of three cycles, without any significant loss in its activity.