Coconut waste–derived sulfonated magnetic biochar: an efficient catalyst for the synthesis of 2,3-dihydroquinazolinone

This work reports the environment-friendly synthesis of nature-derived biochar-based catalyst for synthesis of pharmaceutically significant 2,3-dihydroquinazolin-4(1H)-ones. A Magnetic biochar catalyst was synthesized from coconut waste using a simple hydrothermal reactor followed by 2-step functionalization steps to achieve sulphonated magnetic biochar, Fe@SO₃H-BC. The structural and morphological characterization of the synthesized catalysts was done using XRD, FTIR, FESEM and EDS. The catalytic activity of Fe@SO₃H-BC was studied for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones by condensation of 2-aminobenzamide with carbonyls including acetophenones and aldehydes in solvent-free conditions, resulting in moderate to high yields 83–94% and 70–95%, respectively. The methodology offered advantages by giving an operationally easier and greener chemical route for fabrication of environmentally derived biochar-based catalyst showing notable catalytic activity, recyclability and versatility.