抄録
The carboxylation of indene by carbon dioxide was investigated in the presence of substituted phenoxides in DMF. The reaction took place rapidly at 0°C and was apparently completed within about ten minutes. Indene-3-carboxylic acid was found to be formed in 42-98% yields from indene, depending on the substituents (p-OC4H9, p-OCH3, p-CH3, H, p-Cl, m-Cl, p-CN, and m-NO2) of the phenoxides. The substituent effect upon the interaction of carbon dioxide with the substituted phenoxides was observed. It was found that the yield of indene-3-carboxylic acid increased with substituents of negative σ values, giving rise to a linear relation between the logarithm of the equilibrium constants of carboxylation of indene and the σ values. Relative rates of reaction were compared with the various substituted phenoxides mentioned above. The mechanism of the reaction is briefly discussed.
