Warfarin is an anticoagulant coumarin derivative with two very different uses. In the 1930s, K. P. Link and co-workers at the University of Wisconsin identified warfarin as the constituent of spoiled hay that caused hemorrhaging in cattle. Its name combines the acronym for the Wisconsin Alumni Research Foundation and the “arin” in coumarin.
In the 1940s, WARF developed it as a rodenticide and in the 1950s as a drug to prevent thrombosis and embolism in humans under the trade name Coumadin. The article of commerce is the racemic mixture; the (S)-enantiomer is shown in the figure.
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