A series of experiments based on problem-solving and collaborative-learning pedagogies are described that encourage students to interpret results and draw conclusions from data. Different approaches including parallel library synthesis, solvent variation, and leaving group variation are used to study a nucleophilic aromatic substitution of 1-halo-2,4-dinitrobenzene to obtain aryl-substituted 2,4-dinitrophenylamines. Determining the yield of each reaction in parallel synthesis allows students to make simple structure-reactivity relationships. (Contains 3 figures and 1 scheme.)