Synthesis of Spiro-Pyrazolone-Benzo[ b ]azepines via Three-Component [4 + 3] Annulation of Pyrazolone-Derived Azomethine Ylides with N -(2-Chloromethyl) Aryl Amides

A novel one-pot, three-component [4 + 3] annulation reaction of pyrazolone-derived azomethine ylides with N-(2-chloromethyl) aryl amides has been developed. This method provides efficient access to a series of interesting and valuable spiro-pyrazolone-benzo[b]azepines in moderate to excellent yields with high regioselectivity and excellent diastereoselectivity under mild conditions.