Abstract
8-Nitroquinoline (I) was contracted to 7-nitrooxindole (III) via 3-hydroxy-8-nitroquinoline (II) with hydrogen peroxide in acetic acid. 3-Hydroxyquinoline-8-carboxylic acid (XIV) and its ethyl ester (XV) were also contracted to oxindole-7-carboxylic acid (XVI) and its ethyl ester (XVII), respectively, in the same conditions. On the other hand, 3-hydroxyquinoline and 3-hydroxy-8-methylquinoline (XX) did not undergo contraction in the above conditions.
