GSK Acid and Base Selection Guides

A set of Acid and Base Selection guides have been developed by GlaxoSmithKline [1] using the same methodology that was applied to develop their reagent guides. Factors such as solubility, boiling point, ease of handling and EHS considerations should all be taken into account when selecting the correct acid or base to use for a particular transformation, and the user may sometimes be limited to a small number of options. 

• Where a range of options for the choice of acid or base are available, these guides can direct the user to more sustainable alternatives.   Importantly, these guides also include the pKa  data for all of the individual acids and bases.
• Where choice is limited, the guides can also help the user to differentiate between a class of acids or bases based on their sustainability.

Scoring includes consideration of concerns arising from, for example, the generation of gaseous, flammable or toxic by-products or the disposal via incineration for halogenated acids, via incorporation in the ‘Chemistry Score’.  These issues have the potential to cause significant problems if the chemistry is to be performed on a larger scale.  LCA and waste disposal may also need to be taken into consideration in the case of using an acid or a base as a solvent.