Complex sentence: Citalopram was first synthesized in 1972 by scientists at the pharmaceutical company Lundbeck and it was first marketed in 1989 in Denmark and was first marketed in the US in 1998.
Split into simpler sentences: Citalopram was first synthesized in 1972 by scientists at the pharmaceutical company Lundbeck and was first marketed in 1989 in Denmark. It was first marketed in the US in 1998.