Abstract
A practical synthetic route to regorafenib, in which the target compound was obtained via a 10-step synthesis starting from 2-picolinic acid, 4-chloro-3-(trifluoromethyl)aniline, and 3-fluorophenol, is reported. Crucial to the strategy is the preparation of 4-amino-3-fluorophenol via Fries and Beckman rearrangements using an economical and practical protocol. The main advantages of the route include inexpensive starting materials and an acceptable overall yield. A scale-up experiment was carried out to provide regorafenib with 99.96% purity in 46.5% total yield.
Graphical Abstract
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Acknowledgments
We thank the ACS ChemWorx Authoring Services ([email protected]) for its linguistic assistance during the preparation of this manuscript.