Once you identify which reactant is the limiting reactant, calculate how much product it can make. You can check that you selected the correct reagent as the limiting reactant by calculating how much product the full amount of the other reactant would yield (which should be a larger number)...
In some cases, it may be desirable in practice to initially isolate a compound from the reaction mixture as a pharmaceutically unacceptable salt and then simply convert the latter back to the free acid compound by treatment with an acidic reagent, and subsequently convert the free acid to a pha...