Toward more judicious solvent selection

Scientists at AstraZeneca have taken solvent selection guides to a new level by developing an interactive software tool. Several pharma companies have created tabular guides over the years for their internal use to aid scientists in considering safety, human health, environmental impact, and regulatory concerns when choosing a solvent for a process. The ACS Green Chemistry Institute’s Pharmaceutical Roundtable offers a solvent guide based on those efforts on its website and as a mobile app. As AstraZeneca’s Louis J. Diorazio, David R. J. Hose, and Neil K. Adlington point out, the limitation of these guides is that they are static and tend to be prescriptive, focusing on avoiding certain solvents and barely considering the main purpose of a solvent, which is to help facilitate a chemical process (Org. Process Res. Dev. 2016, DOI: 10.1021/acs.oprd.6b00015). In developing the new guide, the AstraZeneca team started with 272 solvents and experimental and computational data. Using Microsoft Excel, the researchers developed a system to create statistical maps that allow researchers to still focus on safety and environmental impact while selecting reaction parameters to zoom in on the best solvent options to increase reaction rates, reduce reaction steps, steer product selectivity, and improve yields. To make the approach user-friendly, they built a data manipulation tool using the software package Spotfire. AstraZeneca is using the new software tool internally and plans to make it available through the Pharmaceutical Roundtable.