NMR spectroscopy is a powerful tool for characterizing and identifying molecules and nowadays is even used to characterize complex systems in biology. In the experiment presented here, students learned how to apply this modern technique to probe interactions between small molecules and proteins. With the use of simple organic synthesis, students prepared different analogues of the well-known anxiolytic drug, nitrazepam. This study constituted the students' first approach into the drug-discovery field and encouraged the students to think about how to improve the design of drugs in a rational way. (Contains 3 figures.)