New Synthetic Process for Bosutinib

Abstract A new and improved synthetic route to bosutinib is described on a hectogram scale. The key step is the intramolecular cyclization of a 3-(2-aminophenyl)-3-oxopropanenitrile with N,N-dimethylformamide dimethyl acetal to form the 3-cyano-4-hydroxyquinoline ring of 7-(3-chloropropoxy)-6-methoxy-4-oxo-1,4-dihydroquinoline-3-carbonitrile. A practical synthetic method to 2,4-dichloro-5-methoxyaniline is also established. Bosutinib is obtained in 18.0% yield over nine steps from acetovanillone with 98.9% purity (HPLC).