Wouldn’t it be nice if your reactions only created your desired product? Of course the answer is yes, but that is not the reality of synthetic chemistry. Because our chemical reactions yield multiple components, they need work-up and purification to isolate the desired compound.
Most chemical reactions take place in liquid form since compounds in solution are more likely to interact with each other, especially when heated. Reaction solvent choice varies based on reagent solubility and reaction temperature requirements. Because many reactions today require high temperatures, solvents such as dimethylformamide (DMF) and dimethylsulfoxide (DMSO) are frequently used. However, just because a reaction solvent has the proper reagent solubility and/ or a high boiling point does not mean it should be used. Why? Well, as we will show in this post, the solvent itself can alter synthetic efficiency by changing reaction kinetics as well as the number and type of by-products.
In drug discovery, microwaves are common tools for heating reactions to high temperatures and pressures so that it is possible to synthesize compounds in minutes that might otherwise take hours by conventional heating. However, another environment where this is a considerable advantage is in the teaching laboratory. By greatly speeding reaction rates, students can try multi-step synthesis is a single day, and look at the effect of altering reaction conditions on products and yields.