Synthesis of lapatinib using a novel, inexpensive, and environmentally friendly approach

Abstract

A novel and environmentally benign synthetic route for the oral breast cancer drug lapatinib is presented. Unlike conventional methods that rely extensively on organic solvents, the proposed approach predominantly employs water and recycled water as reaction media, significantly reducing the environmental footprint. The synthesis is streamlined into three main steps, enhancing cost-effectiveness and process efficiency. In a fourth step, lapatinib is converted into its ditosylate salt to improve aqueous solubility. All intermediates and final products were thoroughly characterized using IR, ¹H NMR, ¹³C NMR, and mass spectrometry. To assess the sustainability of the synthetic route, green chemistry metrics—including E-factor, atom economy, reaction mass efficiency (RME), optimum efficiency (OE), and Eco-scale—were calculated for each stage. The results confirm that the described method provides a greener and more sustainable alternative for the synthesis of lapatinib ditosylate.