Ring shaped molecules containing nitrogen and oxygen (as well as sulfur) are called "heterocycles" and they are an extremely common building block of pharmaceut

Ring shaped molecules containing nitrogen and oxygen (as well as sulfur) are called "heterocycles" and they are an extremely common building block of pharmaceuticals. They are found in 8 of the top 10 best selling drugs in the USA: Lipitor, Plavix, Nexium, Abilify, Seroquel, Singulair, Crestor, and Cymbalta. Combined sales of these 8 pharmaceuticals were worth $43.2 billion in 2011. http://www.businessinsider.com/10-best-selling-blockbuster-drugs-2012-6?op=1 http://www.businessinsider.com/10-best-selling-blockbuster-d... So developing reliable reactions that build these molecules is, indeed, a useful exercise.