Novel approach to 3,4-dihydro-2(1H)-quinolinone derivatives via cyclopropane ring expansion.

N-(1'-Alkoxy)cyclopropyl-2-haloanilines are transformed to 3,4-dihydro-2((1)H)-quinolinones via palladium-catalyzed cyclopropane ring expansion. The reaction tolerates a variety of functional groups such as ester, nitrile, ether, and ketone groups.