Photochemistry of dimethyl quinoline-3,4-dicarboxylate N-oxides

Abstract

The photochemical rearrangement of 2-methyl and 2-aryl substituted dimethyl quinoline-3,4-dicarboxylate N-oxides has been studied. In methanol or methanol/chloroform solutions the major product was the 1-methyl-or 1-aryl-quinolin-2(1H)-one in which the substituent at C2 has migrated to nitrogen. The yield of these products was increased in a dark reaction subsequent to the irradiation. In acetonitrile solutions the inital major product was the corresponding 3,1-benzoxazepine; subsequent reactions yielded inter alia indole derivatives.