Lithium recovery in dapagliflozin drug synthesis: An efficient and scalable approach

Abstract Lithium is an important component in many industries, including energy storage/electricity, electronics, ceramics, and pharmaceuticals. It is, however, a finite raw material and increased demand, particularly for lithium‐ion batteries, has come with growing scrutiny of its sustainable supply. Although much of academia and industry is keen in its research on recycling lithium from spent batteries, less has been said about recovering lithium originating from chemical processes, such as pharmaceutical manufacturing. Numerous lithium‐based reagents find application in organic synthesis to form CC, CN, and CO bonds. The reagents are crucial for the industrial production of pharmaceutical intermediates and active pharmaceutical ingredients (APIs). However, a significant quantity of lithium is lost post‐reaction and is generally discarded in water waste streams. At present, no such recovery processes are standard industrial practices and consequently a loss not only of resource but also an environmental impact. To solve this problem at a practical level, we established an efficient, economically profitable procedure that can be up‐scaled to recover lithium salts from the aqueous effluent resulting from dapagliflozin synthesis, an antidiabetic drug. The process comprises recovering lithium as Li 2 CO 3 , where n ‐butyllithium is utilized as the reagent for synthesis. We have successfully demonstrated our method at multi‐kilogram pilot scale with high recovery efficiency and product purity. This establishes a viable route for lithium recovery from pharmaceutical production waste, aiding in more renewable and responsible exploitation of lithium resources.