Karl Paul Link

He briefly worked with carbohydrate chemist Sir James Irvine at the University of St Andrews in Scotland and from 1926 in Graz, Austria with Fritz Pregl, inventor of microchemistry and Nobel Laureate.

Finally he spent several months with organic chemist and future Nobel laureate Paul Karrer in the latter's lab in Zurich; during this period Link had tuberculosis, requiring recuperation in Davos.

However, the most fruitful period began when Ed Carson, a Wisconsin farmer, attracted Link's attention to "sweet clover disease", described in 1924 by veterinarian Frank Schofield.

Under the direction of Link, PhD students Harold Campbell, Ralph Overman, Charles Huebner, and Mark Stahmann crystallised the putative poison—a coumarin-related compound—and synthesised and tested it; it turned out to be dicoumarol (3,3'-methylenebis-(4 hydroxycoumarin)).

[2] His work in later years was hampered by poor health (tuberculosis) as he was then relocated to Lake View sanatorium, and upon his return was never able to fully regain his momentum in research.