An improved, high-yielding, and efficient protocol for the production of Regorafenib (1), a novel diaryl urea inhibitor of multiple protein kinases, is described. The highlight of the process chemistry design and development is an optimization of the route for preparing key intermediate 4-(4-amino-3-fluorophenoxy)-N-methylpicolinamide (7) by O-alkylation, nitration and reduction reactions. The developed process avoids using column chromatography to isolate 7, reduces the reaction requirements and is cost-saving, resulting in an increased overall yield from 35.0 to 57.0 % and purity from 97.0 to 99.8 %.
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