The pyrolysis of oxindoles at 850°C. II. Oxindoles methylated at N1 and at C3

Abstract

The products of pyrolysis of 1-methyl-, 3-methyl-, 3,3-dimethyl-, and 1,3,3-trimethyl-oxindole at 850°/0.2-0.4 mm have been examined. 1- Methyloxindole and 3-methyloxindole gave mainly complex mixtures of decarbonylated and rearranged products, but 3,3-dimethyloxindole gave 2-quinolone (52%) and indole (25%). Similarly, 1,3,3-trimethyloxindole gave 1-methyl-2-quinolone (30%).