Green mussel shell-derived hydroxyapatite-CoFe2O4 catalyst: Microwave-assisted synthesis of 2-amino-4H-chromene derivative

The utilization of catalysts in organic reactions represents a widely utilized principle within the concept of green chemistry. This study focuses on utilizing hydroxyapatite from green mussel shell waste combined with CoFe2O4 as a heterogeneous catalyst for synthesizing 2-amino-4H-chromene derivative. The green mussel shells were calcined to produce CaO, which was then utilized as a precursor in the synthesis of hydroxyapatite, and then combined with cobalt ferrite through the coprecipitation method. Diffractogram analysis confirmed successful formation of hydroxyapatite, CoFe2O4, and their composite, validated against JCPDS data. Morphological analysis revealed irregular shapes, while magnetic property analysis indicated a slight decrease in the hydroxyapatite-CoFe2O4 composite compared to pristine CoFe2O4. Catalytic activity assessment demonstrated high yields (up to 88 %) under optimized conditions: catalyst concentration of 7.5 % w/w, reaction time of 15 minutes, in ethanol solvent, and using 300 Watts microwave power. The reusability of hydroxyapatite-CoFe2O4 as a catalyst, supported by the XRD and FTIR analyses, demonstrates its structural and chemical stability after five catalytic cycles, showcasing its potential as an eco-friendly and efficient catalyst.