When choosing the best paths way, Chemists need to try to find:
Processes which do not require a solvent - solvents can be expensive, difficult to dispose of and often cannot be re-used after a reaction has taken place
Processes which use non-hazardousstarting materials - so that the reactions are safer to operate and avoid having to dispose of any unreactedstarting materials
Processes which consist of as fewsteps as possible - this means they are usually faster and moreefficient
Processes which have a high atom economy - in order to avoidwaste products