Going Green in Process Chemistry: Optimizing an Asymmetric Oxidation Reaction To Synthesize the Antiulcer Drug Esomeprazole

Sustainable practices in process chemistry are highlighted by a novel, 9 week team project of 8-12 students, in collaboration with AstraZeneca chemists, in an organic chemistry laboratory. Students synthesize the antiulcer medicine esomeprazole, which involves the asymmetric oxidation of pyrmetazole. To provide insight into the modern process chemistry industry, they propose environmentally friendly modifications to the asymmetric oxidation. Students first synthesize pyrmetazole and then follow a standard oxidation procedure and carry out modified, greener reactions of their choice. They investigate how a change in reaction conditions affects both the yield and enantioselectivity of esomeprazole. Positive student feedback was received and student postlab reports were analyzed over a 4 year period (2015-2018). Results consistently showed that the project provided students with the key tools to develop greener syntheses. This contextual approach not only offers the opportunity to develop valuable communication and team-working skills, but it also gives students creative input into their experimental work. It teaches the important research skills involved in sustainable process chemistry, from reproducing and modifying a literature procedure to identifying green metrics.