1H-1-Benzazepines. The reactions of laevulinic acid and β-benzoylpropionic acid with aniline and methoxyanilines

Abstract

Treatment of laevulinic acid with aniline yields 5-methyl-2,3-dihydro- 1H-1-benzazepin-2-one and 5-(2-methyl-5-oxo-1-phenylpyrrolidin-2-yl)-4- oxo-N-phenylpentanamide In contrast, the reaction between β- benzoylpropionic acid and aniline yields 4-(2-oxo-1,5-diphenyl-2,3- dihydropyrrol-3-ylidene)-N,4-diphenylbutanamide, whose structure is confirmed by an independent synthesis. The yield of the latter type of reaction is enhanced if p-methoxyaniline is used, whereas the desired benzazepine is obtained if m-methoxyaniline is utilized. For example, the reaction between β-benzoyl-propionic acid and m-methoxyaniline yields 8-methoxy-5-phenyl-2,3-dihydro-1H-1-benzazepine-2-one as the major cyclized product.