| Abstract: | The reaction between ethyl 2‐chloro‐3‐(phenylamino)but‐2‐enoate ( 5 ) and aniline gave 4‐methyl‐3‐(phenylamino)quinolin‐2(1H)‐one ( 6 ) and not, as reported earlier in the literature, the isomeric 2‐methyl‐3‐(phenylamino)quinolin‐4(1H)‐one ( 1 ). The latter could be prepared by an alternative procedure. The structures of both isomers were established by extensive NMR spectroscopy including 1D‐NOE, 2D‐HSQC, and HMBC experiments. Consequently, the reinvestigation of the title reaction revealed an unexpected simple access to novel 4‐alkyl‐substituted 3‐(arylamino)quinolin‐2(1H)‐ones. |
