While solvents may get all the limelight as being the largest input to pharmaceutical manufacturing processes, reagents, substances or compounds added to a system to create a chemical reaction, are also important components to focus on when taking the greener route.
Similar to the Solvent Guide, created by the ACS GCI Pharmaceutical Roundtable, which helps chemists choose safer solvents; the roundtable has created Reagent Guides. These guides were created to achieve three purposes, to provide a balanced assessment of chemical methods, to allow easy access to chemical literature or procedures for reagents that end up with a high score in the assessment, and to gain attention for new emerging green chemistry methods. When the first round of guides are complete there will be nine sections to choose from: oxidation to aldehyde and ketones, nitro reduction, n-alkylation, o-dealkylation, ester deprotection, epoxidation, amide formation, Boc deprotection, amide reduction.
So what criteria are these guides assessing exactly? Reagents are looked at based on their utility- how widely used they are by the public, scalability- is the reagent used on a larger commercial scale, and it’s “greenness”. Factors for greenness can include environmental impact, toxicity, availability, cost, etc. All reagents are separated into a three sectioned Venn diagrams labeled with each criterion for the reagents, grouping together reagents that fall into each category, and those that overlap.
Reagent Guides will lead to less waste, fewer worker exposure issues, and much more. Reagents are important because no one has tried to match utility, safety, and greenness to discover a solution for greener productions. This gives scientists a mechanism to make decisions about which reagents they will use for their chemistry, and information about how to minimize impact of their chemistry. These guides are yet another step in a greener direction.
1 Alfonsi, K., Colberg, J., Dunn, P.J., Fevig, T., Jennings, S., Johnson, T.A., Kleine, H.P., Knight, C., Nagy, M.A., Perry, D.A., Stefaniak, M. Green chemistry tools to influence a medical chemistry and research chemistry based organization. The Royal Society of Chemistry, 2008.
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