Observation of differential reactivity of cyclic amines in SN2 and SNAr displacement reactions in the course of synthesizing C-6, C-7 substituted quinolinecarbonitrile MEK1 kinase inhibitors

We have previously reported on a series of 4-anilino-6,7-dialkoxy-3-quinolinecarbonitriles as potent inhibitors of MEK1 kinase. Herein, we describe our synthetic efforts toward a series of 4-anilino-6-alkoxy-7-amino-3-quinolinecarbonitriles. In the course of this work, we were able to rapidly construct a library of 4-anilino-6-alkoxy-7-amino-3-quinolinecarbonitriles by simultaneous or sequential SN2 (displacement) reactions on the C-6 chloroalkoxy moiety and SNAr (addition/elimination) reactions at C-7 with nucleophilic amines.